Barn door rudders and self centering

[dragoncity]

They might 'self center' but I'd be more inclined to think that they would stay in position
due to the mechanical advantage of the number of turns over the steering wheel shaft.
Theres some 'rule' about every extra turn is equivalent to 1000 times the effort to unwind the
rope/chain which should apply here I think. It would also depend upon how 'balanced'
the whole system was, and there must be quite a lot of drag in the chains running along the deck ,
and their weight must come into the 'equation' also.

However, I'll make a point of asking a captain when I'm next in Euchca/
cheers
============================
Hi Brett,
As you say most rudders on the Aussie paddlers were "barn
door" type but I should have thought that if one "let go" of the
wheel (steering that is) the force of the water going past it would
tend to self centre it(providing there was sufficient "way"
on),going downstream may make it a bit difficult to self centre.
Monkey rudders I believe are rudders placed forward of the
paddlewheel on a sternwheeler..............Dai Powell


Brett S Hallett

[Derek Warner]

tend to agree here Brett, but there is a little more - I have some pictures of steering drums
as linked to the ships steering wheel & they appear to be cast iron [or very well worn jarrah]
with conventional link chain slots, so any [water] loading on the rudder and the resultant forces
back to the wheel would apply the same force [less friction] in a radial movment and attempt
to turn or return the ships wheel in the direction of the applied force

Now I did note on the Landline paddler program last Sunday that on a few occasions the skipper
of Pevernsey [I think] was steering and also navigating the S bends when towing a barge, so when
he looked around to check how the barge was placed, another person in the wheel house assisted
with the steering effort - like I think we are pretty spoilt with the power steering in our cars etc
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Just another point on towing barges from the documentry - I did not realise that paddlers had their
towing post near amid ships and yes sometimes say 20' above the deck - Derek

[Mike Mayhew]

Hi you steering guys, I have been reading your comments re large rudders and wether or not they would self centre. Having had many years of practical experience on ships with Barndoor rudders the answer is a very positive YES.the do kick back and can be very dangerous if you do not concentrate on what you are doing. We had a dredger, the Sand Pearl, and her wheel was 5ft diameter with a drum and gearing 2:1 and chains which went on deck then to steel rods and finally chain on to the rudder quadrant[head] the rudder was 5ft deep and 4.5ft in length fore and aft. In a following sea one had to have two people to steer! and a stout rope tail was secured to an eyebolt on deck so as a couple of turns could be made around a spoke to take out the backlash... It was hard work and when comming home with a load and a flood tide in the Bristol Channel ones arms were at least a foot longer after a three hour stint!! Hydraulic and steam steering is so much easier. Hence the need for more than one wheel on some ships Cutty Sark is a good example. A wheel out of control and spinning wildly is not a pleasent sight and the result is often a broken rudder.
Even the Bounty had releiving Tackle on her rudder tiller. Look closely at steering systems of old coasters, in the linkage on deck aft you will see large shock absorbers fitted. [springs]
So Leighton like the Murry River boats lets have a Big wheel 5ft? Hope this little bit of personal infro helps clear up your questions.

The Old seafarer him self WaverleyMike.

[Leighton]

Hi Mike thanks for that.
I had allowed for a 6' dia spoked wheel. A paddle steamer aint a
paddle steamer unless she has a wheel you can hang onto.
The design is such that 2' will be below the floor and 4' above (so
short people can see over the top!).
Thanks for your input.
Leighton