The Ben Ain Build

[Bunkerbarge]

Many thanks for the kind words gents.  The build has taken four years so far and I guess another two or three will be required to complete it.  Not easy fitting in such a project with everything else you have to do during a seemingly short leave!

Anyway as for the valves, the first valve in line from the tank, apart from the isolation valve, is a pressure regulating valve.  The heat I am going to transfer from the seperator will hopefully increase the pressure of the gas tank or at least slow down the rate the pressure falls due to the cooling effect of the evaporating gas.  The regulating valve is supposed to smooth out any fluctuations in the gas pressure from the tank and ensure a regular pressure to the burner.

The second valve is a Cheddar Electronic Gas Valve and is operated by the pressure in the boiler which, via the servo, turns the gas from a full flame setting to a pilot flame setting.  The set point of the controller should then maintain the boiler at a reasonably steady pressure without wasting any gas.

Basically the first valve is controlling the gas pressure in the gas tank and the second one is controlling the steam presure in the boiler.

I have sailed the boat with the  second valve in line but the gas pressure regulating valve and the heat bridge has not yet been tried out.

[Bunkerbarge]

Nine: The Stand

At this point in the construction the model was destined for display at a model engineering exhibition so it was decided that a more appropriate stand would be required to display it at its best.  The stand used so far in the construction was simply made from the profiles supplied with the plan to produce two upright supports made from sections of teak plank.  These were cut to shape, spaced with suitable dowels and attached to risers to give a slightly more appealing design as well as lifting the model a little bit higher off the base board.

The base was simply a piece of laminated pine board, varnished, with a block of teak fitted for the name plate.  Felt pads were added to the tops of the profiles to protect the hull and a brass name plate was added to the teak block.  This proved to be a suitable stand for working on the model and would later form the basis of a carrying box but it was not the best for display purposes.

It is often the case with model boats that the stand is not given the attention it deserves.  It is the means of displaying your model to it’s best so it should enhance the model, look professional and present the model at it’s best.   One of the most impressive methods of presenting a model ship, and precisely why it is used in museums the world over, is to place the model on pillars.  This allows the model to be elevated to a level that allows easy views of the entire hull and presents it as an object free of it’s base.  There are many ways of interpreting the pillar design but one of the most widely used and one of the most attractive is to use brass pillars on a polished wooden base.

The first piece to obtain was a suitable piece of teak to form the base.  This was procured from a ships wood store, and even then required laminating to produce a piece of the required size, and was cut to size and thickness before a router was run along the edges of the base to finish it off.  This base was then given three coats of a polyurethane varnish, rubbing down between coats to give an extremely durable and waterproof finish. 

Next the attentions were turned to the pillars and the best method of design.  The idea was to come up with a simple yet elegant design that could be easily produced on a model making lathe.  The final configuration was generated from 25mm round bar stock, taken down to two smaller diameters with a tool profiled to give a similar radius at either end of the cuts.  In this way a single tool could be used for the entire process, generating a simple pillar that complemented the complexity of the finished model. 
 
Four pillars would be used, two along the keel and two across the midships section so stock brass was prepared for the machining.  When all four pillars were turned, drilled and tapped to M8 in the base and parted off the top faces were machined to give exactly the correct heights to support the model evenly.  The final machining process was to mill a slot across the top face of the two pillars that were to hold the keel of a suitable height and depth to locate the keel.  Once the machining was completed all four pillars were sent away to a local metal finishers to be polished to a high degree.

On their return the base was marked out for the four positions and drilled, then counter bored to clear the heads of the M8 screws, before fitting the pillars in place and lining up the slots in the centre line pillars.

A final finishing touch to protect the hull detail from the pillar was to cut to size pieces of balsa wood, glue them to the tops of the pillars and paint them black with some enamel paint.  This provides a degree of cushion for the weight of the model and protects the surface of the hull from abrasion and scratches.

Finally the name plate was stolen from the building stand and fitted to the display stand to finish it off. 

The materials and techniques used in the stand are available to the majority of model makers with a reasonably equipped workshop however if such equipment is not available then alternatives can be sourced for the various components.  The most important considerations are to make a stand, within your available resources, that will present the model at it’s best and look as good as you can make it.

[Bunkerbarge]

Ten: Quarterdeck Superstructure

Before progress could be made with the Ben Ain a significant decision had to be made, namely do I use the supplied fibre glass moulding for the quarterdeck superstructure or scratch build a unit.

The first part of the operation was to fit the coamings to the deck opening in exactly the same way as was done with the main hatch opening.  Vertical 25mm coamings were fitted and glued to the internal opening beams, ensuring that they remained vertical during the drying process and webs were added at the corners to ensure rigidity of the structure to resist the forces involved with fitting and removing the superstructure.

The supplied moulding had a few issues that required addressing, such as the vertical sides were not straight and vertical so required pulling in with an internal frame, the lower edge was not square to the deck so it had to be dressed up to fit, the forward bulkhead was square to the top so it did not match the angle at the back of the bridge unit made with the deck, the top was flat and not cambered and the moulded detail was not as crisp as I would have preferred with the door openings and plate joints being square to the top rather than vertical as they should be.  Combined with this the unit was also a bit on the heavy side so I decided to have a bit of a play around with some plywood to see how difficult it would be to manufacture a unit from scratch.

The unit looks to be a simple enough shape but the ends should be vertical when sat on the slightly angled quarterdeck.  This means that the forward and aft bulkheads should also be slightly angled and all the plate detail and door openings should also be vertical when the unit is fitted.  I started by making two side plates from the original moulding and marked out the openings.  The forward edge was angled to butt up to the bridge unit and the aft edge was angled similarly.  Two pieces of 10mm x 10mm stock wood were fitted at the aft edge with 5mm x 5mm supports glued to them to keep them square with the ply bulkhead as the aft edges are curved so will have to be carved from the solid wood. The width of the unit was determined from the moulding and the difference measured from the deck opening determined that the ply bulkheads needed to be 5mm from the coaming so an internal frame of 5mm stock was used to space the sides.

Once the dimensions were settled all the openings were cut from the sides and pieces were made for the forward and aft bulkheads, with a suitably curved top, and the box unit was glued together on the model.  The separation of the side bulkheads was set by fitting transverse beams to support the boat decking as well as additional internal frame work and these were used to support half bulkheads with curved top edges which would give the support and curvature for the cambered top deck.

At this point the ply top was cut to shape and the correct position of the funnel opening was determined and cut out with a hole saw and sanded to suit the supplied plastic pipe for the funnel.  Once the fit of the top was finalised the top deck was glued down and held to the curved formers until the glue had completely set.  When set the unit was finally removed from the model and the quality of the fit to the model determined.  From this point on there was no question that the unit was going to be a success and would produce a lighter and more accurate item than the original fibre glass moulding.  Internal bracing and stiffeners were added to ensure rigidity and a weir was build around the internal funnel opening from 5mm x 5mm stock wood.  The aft corners were rounded off to a 5mm radius by using a sanding block made from sandpaper glued to a piece of board.  This enables an even radius along the whole length of the corner and makes for blending the radius to the flat bulkheads a lot easier. 

The plastic tube of the funnel was cleaned up and roughened with emery cloth before inserting into the tight fit of the hole in the deck.  Once the position was matched to the boiler flue the unit was removed and Isopon resin was poured into the weir to ensure a rigid joint and location with the plastic tube.

The funnel was progressed with the addition of the white metal fittings included with the kit with the position of the fittings being determined from the plan.  The ships whistle, cast in white metal, would have to be painted to resemble brass so this was scratch built from bits of scrap brass tube glued together to give a neater unit.

The next structural item to be made was the engine room skylight which was built up from the kit parts with the openings being held open with stays and the white metal fastenings being replaced by M2 screws, nuts and washers to give a much crisper level of detail for the items.  The location on the top deck was determined and an opening was cut into the deck to allow through ventilation from the boiler space below when the model is steaming.  The internal surfaces were painted with a coat of primer then radiator enamel before gluing the unit to the top of the superstructure.

The bunker opening at the forward end of the superstructure was built up next similarly to the kit instructions with the difference that the transverse beams were laminated from planks, which enabled them to be formed to match the curvature of the camber.  The bunker opening frame was glued in place with internal supports for the hatch boards also added.  Once this was in place a semi circular plastic moulding was added around the top edge, finishing the deck edge off and following the curved aft corners and the camber of the aft bulkhead.

The final significant part of the unit was to fit the last piece of planked deck on the aft port quarter of the top deck and this was made up in exactly the same way as the other decks had been constructed from 5mm x 1mm planks of lime, spaced with 0.5mm plasticard pieces and the caulking made from white PVA mixed with black powder paint.  The final surface was sanded down to reveal the planking below and the deck given three coats of polyurethane varnish.

With the planked deck finished the structure of the unit was considered as complete and the detailed fitting out of the unit could be commenced.

[Eddy Matthews]

I'm not sure if there's really a lot I can say, except that the model is really progressing nicely, and is obviously the work of a real craftsman - Well done Bunkerbarge!

I'm glad to see you've started to post more progress reports, and I'm thoroughly enjoying reading about the build and browsing through the photographs...

Best wishes
Eddy

[Bunkerbarge]

Thanks for the kind words Eddy.  Unfortunately I only get chance to work on the model when I am at home on leave and it has to wait for the three months when I am away at work.  Consequently it is a bit of a slow progress but I do try to get a bit of time on it when I am at home.

Now I'm back at work until September so the next update won't be until at least November.  Still I have to put petrol in the tank somehow!

[Bunkerbarge]

Eleven: Quarterdeck Superstructure Detailing


Once the main structure of the quarter deck accommodation unit was completed it was time to start work on the detailed fitting out of the unit.  I wanted to add riveted detail to match in with the rest of the model as well as emulate the original fibre glass unit as well as add scribed panel lines to follow the plate detail. 

The first step was an overall two coats of grey primer to show up the imperfections and cover up the building markings so that scribing could be done that bit more clearly.  The primer was sprayed inside and out after first masking off the boat platform support beams and the wooden decking and protecting the inside of the machinery space skylight.  A gentle rub down with fine grade wet and dry was done between coats and it was decided that the remaining grain of the wood still visible would be suitably covered with the three coats of matt enamel to be painted on.  Once the primer had dried the panel lines were all scribed on the surface using a small flexible steel rule and the back of a Stanley knife blade.  Care was taken to ensure that the vertical panel lines on the bulkheads were actually vertical when the unit was in place on the angled deck and therefore lined up with the edges of the door openings.

Next was to add the detail to the sides of the structure such as the doors and handrails.  The doors were cut from thin ply and dressed up before being fitted with the white metal fittings such as hinges and handles supplied in the kit.  A number were deliberately left open to allow viewing of the insides of the model when in operation as well as to assist in the ventilation of the machinery space when under way.  The handrails were also the kit supplied white metal supports with the supplied plastic coated fine rod for the handrail itself.  The fittings were all glued in place with araldite after first carefully marking out and drilling the bulkheads to suit.

Once the doors and handrails were in place the first coat of enamel was brushed on, once again with a small flat brush to generate some surface texture as well as to ensure that all the little nooks and crannies were covered.  This gave another opportunity to see how the scribed panel lines were looking as well as to determine whether the wood grain was going to be completely covered with the final two coats of enamel.  Once the first coat had dried completely it was time to get out the cyano gel and add the rivet detail to the panel edges.  Care was taken to try to keep the beads small, regular and consistent, not always easy when your hand is getting quite weary.  Once that was done around the bulkheads and the top deck the next coat of brown enamel was brushed on before finally going over with the orange top coat of enamel.  The wood grain had now all completely been covered and the surface could pass off as plated steel.

The rivet detail added to the steel work was suitable for the accommodation structure but would have been far too cumbersome and out of scale if added to the funnel, which would almost certainly be fabricated from a thin gauge sheet steel.  I tried to find relevant pictures of the structure of a period funnel in vain so made the decision that the sheets would almost certainly be held together with some form of straps to support the riveted edges and the only decision was then to estimate a size, spacing and whether to consider a single or double row.  I eventually settled on a single row, fitted to a strap so made up some lengths of suitable strapping from the paper stock supplied in the kit for the steel decking.  The edge of the paper was trimmed before scoring along it with a ponce or pounce wheel after offsetting the steel rule by approximately half a millimetre and then finally cutting the strap off by an offset of another half millimetre.  This gave a one millimetre wide strap with a row of rivets along the centre line.  These straps were then cut to length and glued onto the funnel structure, with the rivets proud, with cyano after estimating a likely plate configuration.  This would at least add some detail to the funnel surface and give an opportunity for some weathering to be added to highlight the detail at a later stage.

Although the inside of the structure had been sprayed with two coats of primer no other paint had been applied since then mainly because I wanted to complete the electrical installation before any further painting.  I used some circular plastic bulkhead fittings off the shelf, removed the supplied 3v lamps and replaced them with 12v grain of wheat lamps.  It is my intention to use 12v lamps throughout the model and supply them with a 7.2v pack.  This gives a reasonable period glow, as I am assuming from the age of the vessel that most, if not all, lighting would be from oil lamps, as well as ensuring as long a life as possible for the lamps themselves.  The wiring again was made up from old telephone cable, twisted together, and arranged in two circuits.  I want to switch the accommodation and navigation lights separately so the internal lights were wired up in parallel and the stern light was given a separate supply.  All the wires were held in place before being completely covered over with araldite to ensure a resistance to heat and moisture effects.  The exact arrangement for getting the power into the circuit has not been decided at this point but I want to devise an arrangement whereby some form of contact is made when the housing is dropped in place on the model.  I very much want to avoid having to connect and disconnect cables from screwed connectors to remove the housing from the model, which always seems to be a clumsy operation and prone to damaging parts of the model.  The stern lamp was a purchased brass item, which was a lot more clearly defined than the white metal piece supplied in the kit, which was painted up to look like copper and a clear lens made from thin acetate sheet fitted.

Also at this time the ring bolts were fitted around the structure, which were to eventually take the mast and funnel shrouds.  I intend making these from picture hanging wire so I will want to have a small amount of tension in them so the ring bolts have to at least be secure and capable of taking this tension.  The supplied white metal ones were replaced with items made from thin brass wire, glued into the surfaces of the superstructure and the funnel ring.  They were glued with araldite giving a very strong bond and a blob was added inside the structure to secure the ends of the ring bolts.  The large ring bolts for tying down the lifeboats were also added but the kit supplied white metal ones were used here as they are not going to be required to have any strength.

The next job was to start working on the boat platforms and here once again the vertical supports for the ends of the beams were supplied as white metal castings.  These were quite heavy and would take quite a bit of dressing up to fit the ends of the beams as well as being a bit exposed when the structure is removed for access to the model.  Because of this I wanted a really strong bond between the supports and the beam ends so I decided to scratch build them from wood.  The outside flat vertical faces were cut from coffee stirrers with the ends being trimmed to size and angle to suit the sloping deck.  The ribs on the inside were cut from 1mm x 1mm stock and glued to the back before gluing the supports in place on the beam ends, after trimming them to length, taking care that they remained in the correct position as the glue dried.  When they were secure I made some knees from stock strip wood after making a circular cutter out of a piece of stainless steel tube.  Tapping this with a hammer onto the strip wood gave a very neat and consistent curved edge to the knee so these were then trimmed to size before gluing them to either side of the vertical supports at the beam ends.  The white metal profile pieces from the kit were finally added to the base of the supports with a spot of araldite.  The two davit supports were also constructed from wood for the same reasons as the vertical supports with these being fabricated from more coffee stirrers and short sections of cut brass tube of such a size as to allow the main tube to slide through it.  These were all glued together with araldite onto the kit supplied bulwark saddle pieces and attached to the superstructure with wood glue.

As I particularly did not want paint to mark the platform planking I measured out the plank spacing and then painted up the platform supports and the davit supports leaving gaps for the platform planking to be glued to the support surface.  When the paint was dried the planks were added and the ends dressed up before varnishing the planks with two coats of satin and one coat of matt polyurethane varnish.  The next job in this area was the addition of the boat supports which were made from coffee stirrers and strip wood planks after carefully cutting the boat hull profile out of the vertical piece.  These I particularly wanted to show as being fitted to the platforms with bolts so I trimmed down some brass M2 screws, cut off the cheese heads and fitted nuts and washers to either side.  These then made a particularly effective looking bolted fastening for the boat supports and will look particularly effective when finally weathered.

The next job on the boat platforms was to put the davits together and decisions as to the arrangements had to be made next.  The kit did not include any falls which would have almost certainly consisted of a couple of double blocks with boats such as were fitted to the Ben Ain so the possibilities of making them had to be thought about.  I had in my spares box a very old packet of wooden double blocks for use with sailing ship rigging which looked about the right size for 1/35th scale double sheeves.  The fact that they did not actually contain sheeves did not really matter because when they were rigged with suitable diameter rope this fact would not be visible.  The first stage was to add the dead eye so a piece of thin wire was wound round a former to create a loop before winding around the wooden block and then twisting the tails together on the other side.  A blob of araldite was then applied to first one side and then, when set, to the other to create a rounded block shape.  The twisted tails were snipped off and the end dressed up on a piece of fine sandpaper before drilling a hole to accept the swivel hook, made from domestic copper cable core.  Another blob or araldite was added to the end and the swivel hook inserted through the blob and into the drilled hole.  This gave a nice rounded block with a dead eye in one end and a swivel hook in the other, perfect to make up a block and tackle set of falls.  The blocks were painted black and rigged with a suitable diameter cord, which was left with an appropriate length of tail.  The tail was coiled and bound and given a twist around the fall ropes to keep the whole thing neat and as you might expect to see it in a stowed position on a ships boat.

The ends of the davits were also modified to remove the original castings which enabled the addition of an eyelet to take the falls.  The ends were prepared and dressed up straight before a copper tube with a hole drilled through it was araldited to the end.  The davit was then also drilled through the end and an eyelet added, which was actually a brass handrail support from a larger model.  This was held on the top with a suitable brass nut which also located the tab fitted to allow the slewing ropes to be attached.  When the davits were completed they were painted up with the three coats of matt enamel before fitting the falls and placing them in the support brackets.

The final touch at this point was to paint up the funnel so a mix of matt red and earth was made to take the harsh edge off the red paint and tone it down to a slightly more realistic shade.  The two coats were deliberately put on sparingly so the over painted black below it showed through slightly, which will provide a far more realistic base for the final weathering.  The white of the Maltese Cross was also toned down with a few spots of matt earth to prevent it looking quite so stark.  The vent pipe and the whistle were then glued to the front of the funnel and given a coat of tamiya clear smoke to also better prepare them for final weathering.  This also gives a much more realistic patina for the brass whistle and acts rather like a wash in the way that it holds in the shadows and recessed detail.

[Eddy Matthews]

Bunkerbarge, you may be away from home for months at a time, and only work on the model periodically - But my word, when you post a build update you certainly go to town!!

With every little detail covered in-depth it will be a great resource for ideas and techniques that will appeal to many for other builds. So thankyou for taking the time to explain everything so fully.

It's really starting to take shape, and you should be proud of your achievements...

Regards
Eddy

[Bunkerbarge]

Thanks for the feedback Eddy, very much appreciated.  Next installment sometime next year!!

[Bunkerbarge]

Twelve: More Engineering

Once again as the model progressed it became apparent that more aspects of the engineering required attention.  The first concern was that the safety valve was still located at the front of the boiler and, although I was prepared to remove this along with the pressure gauge before removing or replacing the boiler in the model my concern was where the steam would escape should the valve ever lift.  Consequently I wanted to move the safety valve back towards the funnel where it could then be easily arranged to vent into the funnel space.  The problem was again a lack of available spare fittings on the boiler and I particularly did not want to move the main steam stop valve off the boss it was screwed into. 

After considering many possible combination units of a home made valve assembly incorporating the safety valve I came up with the very simple idea of making a connecting piece that would mount both the existing main stop valve and the safety valve.  The mounting was to consist of a female to female connector with a screwed conical fitting silver soldered into it.  I drilled the side of the connector to suit the cone of the screwed fitting which would locate the piece as well as give additional strength to the joint.  The screwed fitting was arranged at such an attitude as to give the required angle to the main stop valve when it was fitted and the connection was silver soldered to give a neat and strong joint.  This fitting now screws into the available boss on the boiler via a threaded connection and the safety valve simply screws into the available top of the fitting.  The main stop valve connects to the screwed fitting and the steam outlet pipe reconnected to the valve.

The other significant modification was the filling arrangement for the on board gas tank.  I have always had a particular dislike for the ‘Ronson’ type filling valves, be they fitted to a cigarette lighter or a model gas tank.  When you think about it all you are doing is inverting the purchased gas canister to allow liquid to flow then using the fitting on the canister you are opening the Ronson valve to allow the liquid to flow into the on board tank.  The problem is if liquid is to flow into the tank then the displaced gas must be allowed to escape somehow.  Because this does not happen the liquid is constantly spitting and blowing out as gas is trying to escape through the open valve at the same time as the liquid is flowing in.  I have already modified the filling arrangement for the tank by filling through a clear hose into another valve and it quickly became obvious that the liquid would not flow very easily as the displaced gas could not escape.

To resolve this the Ronson valve was removed, at which point I noticed with surprise that the valve was not fitted with a dip tube, and the boss was drilled and tapped to accept a 5/16th x 32 tpi standard 90 degree globe valve to which a dip tube had been fitted.  The idea of this valve is three fold, firstly it allows gas to escape at a controlled rate while liquid is flowing into the tank, secondly when liquid is seen spitting out of the valve you then know that the tank is full of liquid and finally the dip tube guarantees a liquid level and hence a gas space in the tank, thereby ensuring that the tank is never completely full of liquid and hence liable to being hydraulically locked.

I tried out the new valve with my camping gas canister, filling through the valve that had been used in the past with the new valve very slightly cracked open.  I was surprised at just how much more quickly the liquid was seen to flow through the clear hose so obviously allowing the liquid to displace the gas worked well.  After a few minutes liquid was seen spitting from the valve so at that point I knew that liquid was at the level of the dip tube so I stopped filling.  Simple, effective, considerably safer and a lot quicker than using the Ronson valve so I was very pleased with the modification.  The valve will be plumbed into an overboard pipe to ensure that a build up of gas inside the hull does not occur, making the arrangement considerably safer than the original.

The final modification was the fitting of a new speed regulating valve on the engine.  The existing valve with the aluminium body has been attended to on a number of occasions and, although improvements have been noted it still seems to insist on leaking from the valve face.  Modifications such as fitting a brass running face had limited success but one came loose and one became blocked with the araldite used to fit it!!  The only real solution was to manufacture a brass bodied valve and a good friend, who happens to be a superb model engineer, helped out by making a beautiful perfect copy of the aluminium body in brass.  This was fitted to the engine and run on the bench before putting back in the model and proved to be a huge improvement on the original arrangement.  The valve still leaks slightly in the neutral position but it is significantly better and when the plant is removed again a bit more attention should improve it even more.

With the new modifications in place it was time to give the plant another couple of runs in the model to get a bit more of a feel for how the plant is operating.  The boiler was filled from the feed tank, the separator tank emptied, the lubricator filled and the gas tank filled with the new arrangement.  The boiler was taken up to pressure, the gas regulating valve turned on and the engine run, using the normal servo’s and control system.  This was actually the first opportunity to observe the effect of the heat shunt, fitted to the separator and the gas tank to offset the effects of the gas cooling, and it surprisingly worked very well.  After the engine had been running for approximately 10-15 minutes the pressure in the gas tank was noted as rising from 25 psi initially to 50 psi with no discernable affect on the burner performance so the heat shunt was obviously doing it’s job, as is the pressure regulating valve fitted to control the varying tank pressure.  The only remaining concern from a technical point of view is the tendency for the steam exhaust to spit water out of the top of the funnel.  This is obviously as a result of the fact that the separator tank is actually further away from the engine outlet than the ideal bit it is hoped that when the pipe work is completely lagged that this will improve significantly.

[bogstandard]

Richard,

I don't think you will ever eradicate leakage completely in the neutral position on that type of valve, as the valve is acting like a pressure relief valve. So unless you tighten up to overcome the steam pressure in the line it will still weep slightly.
It is a catch 22 situation, have it leaking slightly in neutral and retain a nice smooth action, or tighten it up to stop the leak and have a difficult to move control valve.

It is for that very reason I have tried not to use that type of control valve, and wherever possible now, I go for a fully enclosed spool valve, which cures the problem completely.

a good friend, who happens to be a superb model engineer, helped out by making a beautiful perfect copy of the aluminium body in brass

Is it someone I know?      


John

[Bunkerbarge]

I was worried that if I told them the engineer in question would be inundated with a continuous stream of requests for similar jobs!!

I know what you mean about the leaking at neutral.  As soon as you operate the valve the pressure on the face is relieved as it goes to the engine so not surprisingly you get the leaking at neutral.  I've not yet given it the toothpaste treatment, that's for when it comes out next time, which I hope will help but I'm not expecting it to stop completely.  It is a lot better niow though so I'm still very happy with the improvement.  I have also brought the pressure set point down on the gas regulating valve so it works between 35-40 psi and that helped as well.

[Bunkerbarge]

Thirteen: Lighting Installation

One part of any such project that seems to progress in the background alongside everything else yet remains a separate and independent item is the electrical installation and in particular the lighting.

I decided right from the start that I wanted to incorporate a lighting system but did not pay a great deal of attention as to how I wanted to arrange this when I first started building.  The one decision that I did make however was what type of lamps to use.  I could have gone for the simple and reliable path of LED’s but for a 1920’s coaster which would almost certainly be using oil lamps I thought the bright blue light from an LED would not be an appropriate light.  The best way to achieve the type of light I was after was to use 12v incandescent lamps but use a lower voltage across them.  This would have the advantage of producing a dimmer light, more in keeping with the model’s age, and it would also hugely increase the life of the lamps.  This was to be particularly significant as I was going to seal the lamps in for the life of the model.  This being mainly driven by the fact that a number of lights were to be in locations that access could not possibly be achieved after the model was completed. 

Initial experiments tended to indicate that a six volt pack would produce the required degree of illumination so a simple four “AA” pack battery holder would be perfect for the job.  The lamps seemed to be suitably bright enough so I started to install the initial lamps in the hull as the building progressed. 

I have always believed in completely encasing wiring for lamps such as this in a resin to protect the wiring for the life of the model and the lamps were arranged to be located in a reflective housing to protect them and to enable the best from the lamp.  I therefore started to install lamps in the hull inside paint pot lids and ran the cables back to a central location for connecting at a later date.  Lamps were fitted behind the ports in the fo’c’sle, behind the ports in the mid ship hull and were incorporated into the bridge unit and the aft accommodation unit. 

The lamps in the aft accommodation were a bulkhead lamp fitting with the 3v lamps removed and 12v lamps fitted instead to give a similar level of illumination.  Other lights fitted during the build included the red and green bridge navigation lamps, which were turned brass items with a thin acetate sheet fitted over the opening after the insides had been painted.  The lamp itself was painted up to resemble painted copper with some of the paint chipped and a degree of weathering added before putting another 12v lamp inside after feeding the cables up through the back of the bridge housing.
     
Once the aft accommodation lamps had been fitted the whole concept of how I wanted to operate the lights had to be addressed and decided before taking the model any further.  I was particularly after a level of realism in the use of the lights so consequently I wanted separate circuits for separate uses.  I decided on one circuit for all navigation lights so the two bridge navigation lamps, the aft anchor lamp and the forward mast lamp were to be connected together.  All accommodation lighting was to be common and independently switched so that the ship could be alongside without navigation lights but with accommodation lights and finally the light on the bridge had to be independent.  Bridge lights are very rarely lit except when in port so I particularly did not want the bridge light to be lit when the ship was underway.  This therefore gave me three circuits, more than enough for such a simple old steamer! 

The next decision was whether I wanted the circuits to be operated via the transmitter or manually.  Part of this decision was based on the fact that using a Dx6i meant that I would be switching lighting circuits with a proportional channel, which didn’t seem right, as well as requiring either servo’s and switches or electronic relay’s to operate the circuits.  All more complexity and weight in the model.  Consequently I opted for the circuits to be operated manually from switches located in the main hatch.  Obviously you don’t then have the convenience of switching circuits on and off when the model is under way but I thought that was a price I was prepared to pay for the sake of keeping the internals that bit simpler.  I think I have enough complexity in the steam plant without going down the same path with the lighting circuits as well!

It was also at this point when I decided to use rechargeable batteries for the lights so fitted four “AA” rechargeable batteries in the holder.  Then I noticed that the lamps were now getting too dim for credibility and then realised of course that four rechargeable “AA”s only gives 4.8 volts.  Time for a rethink. The solution was to go for a 7.2 pack, which I tried but thought that the lights were too bright so eventually removed a cell and settled on a 6V 5 cell rechargeable pack.  This was partly dictated by the fact that the lighting battery is also supplying the gas control valve and 7.2 v proved to be two much and the servo did not operate smoothly so consequently the 6v pack seemed to be the best compromise all round.  A charging connection was also fitted to enable a normal Tamiya type charger to be used to charge up the battery pack with all items remaining in place in the model.
Having decided on the circuits and power the final main decision was how to get the power to the removable items such as the bridge and the aft accommodation units.  I have always particularly disliked the idea of trying to disconnect wires from connecting blocks to enable parts of a model to be removed and have recently tried the method of plugging cables into a socket located within the model but for this I really wanted the complete convenience of being able to remove and replace the parts of the model without having to become involved in the lighting at all.  The only way I could see this happening was by using a plug and socket connector unit with one being permanently mounted in the removable unit and the other being mounted in the model.  I eventually obtained some very neat little six pin plug and socket units and set about how I was going to mount them in the model.  I only used the centre four pins as I only needed two circuits to be completed so the connectors were wired up and mounted in holders ready to fit.  First the unit was fitted in the removable aft accommodation section and, when set, the plug was assembled. 

Then the accommodation was placed on the model and the other side of the plug glued to a mounting inside the aft coaming.  It actually proved to work very successfully with the circuit being made when the accommodation is dropped in place which can also be removed without worrying about any of the lighting circuits.  The two circuits were then tested and the accommodation lights and the aft anchor light worked fine from the two switches in the main hatch.

All that remains is to fit exactly the same plug and socket unit below the bridge for the two circuits in that piece!

[Bunkerbarge]

By the way the absolutely beautiful brass control valve was made by our very own Bogstandard.  If you ever get stuck with an engineering issue drop him a PM, you'll be surprised at just what he can make!

[derekwarner_decoy]

Well PD's ....now the news is out....YES it's coals to Newcastle... .....many little shiny brass bits for my PS Decoy build    are also from CREWE engineering [Bandit, Vinnie & Bogs] then posted 1/2 the way around the world.............

Could ask not for better quality & tolerancing.........& we have  a few laughs via PM's......frankly the costing $$$$$$ even with the air parcel post & insurance is similar to what I would pay in OZ

Thanks John...... ....................Derek

 

[Bunkerbarge]

Chapter Fourteen:  The Flue

Having made the modifications to the steam plant in Chapter 12 it was time to make the most of them and finally get the flue sorted out.

The whole idea of moving the safety valve closer to the funnel was to enable me to vent the safety valve up through the funnel rather than have it lifting and venting inside the model, which could have made a bit of a mess inside, so now it was time to make the arrangement to allow this.  My idea had always been to make a pipe from a cover that went over the safety valve and pipe it into the boiler flue so I set about having a good root through all the copper pipe fittings in B&Q to see what I could use.  I was very pleasantly surprised to come across a copper fitting that was a 45 degree bend with a flared end that sat very nicely over the safety valve body.  I didn’t want to actually attach it to the valve but simply have the new pipe sat over it, which would enable me to gain access to the valve reasonably simply by removing the flue from the boiler.  Then I sourced a piece of copper pipe that slid nicely into the other end of the fitting from the scrap bin at work and I had the bits to start with.

The first thing I wanted to do was to secure the steam exhaust pipe running up the centre of the flue to prevent it from rattling around while I worked on the new pipe so I looked through my metal bits and bobs and came up with an old brass capstan arrangement.  I drilled out the centre boss and then cut the main flue tube to length to suit the model funnel and cut notches around the circumference to match the arms of the capstan.  The pieces were then assembled around the steam exhaust pipe with a plastic metal putty material to hold the whole assembly in place until it set.  I had a play around with soldering the parts but it proved to be extremely difficult with the high number of pieces to be secured simultaneously as well as the significant difference in component size making for difficult heat transfer issues.  The plastic metal putty method is certainly not quite as strong as solder but for an item such as this which is not taking any load it is perfectly adequate and enables complex assembly’s such as this to be put together easily.  Once the putty had set the protruding ends were trimmed and the excess putty filed down to give a neat arrangement for holding the steam exhaust pipe centrally while having a minimum of effect on the flue cross sectional area.

Then it was time to fit the flue to the boiler in the model and mark out where the new safety valve vent was to fit.  I wanted a smooth path for the safety valve outlet to minimise the possibility of a back pressure effect so it was important to have the pipe entering the flue at a shallow angle and ensure the steam did not vent back into the boiler furnace space.  The copper fitting was held loosely in place on the valve, the pipe length determined and the entry point into the main flue was determined.  The flue was then removed again and the penetration into the flue was started with a drilled hole.  This was then opened out with a tapered reamer, which has the advantage of cutting on the edge so it could be held at the appropriate angle, and a suitable elliptical penetration was generated to fit the vent pipe.  The vent was cut at a matching angle and to length before the pieces were assembled loosely again on the model to see how it all fit.  Once again the challenge here was to ensure that the pieces were perfectly aligned so it really required securing while in place on the model so the plastic metal putty method was used to hold the bits together.  Spacers were inserted around the various parts to ensure perfect alignment before placing small amounts of the putty around the joints to effectively ‘tack’ them in place.  Once again there is no loading on the pieces, the pipe simply sits over the safety valve so I’m reasonably confident that the plastic metal putty will be up to the job.  If it falls apart one day I’ll let you know.  The assembly was removed again and the joints were completely sealed up with the putty to ensure  a degree of strength.

Once the structure of the flue was completed it was time to lag the assembly and the most effective way of doing this was to wrap the components with string to give a neat and tidy covering, especially around the joint, before finishing off with a wrap of sticky backed foil tape.  The final unit looks surprisingly realistic but more importantly I now have a flue that combines the boiler exhaust, the steam exhaust and the safety valve vent into a single pipe.

Interestingly the final thing to mention here is the fact that although I go on and on about pre-planning I fell foul of my own lack of it.  I always thought that there was plenty of room inside the aft superstructure unit to accommodate the safety valve vent but I’d seriously got it wrong.  The new vent pipe interfered significantly with the superstructure and I was incredibly lucky to be able to remove material from the inside of the unit without it being visible externally.  Talk about a huge sigh of relief.