Boiler types

[kiwimodeller]

Hi, I have just acquired two ACS boilers. One is what I would call the conventional model boat boiler, a 6" x 3&1/2" centre flue type with cross tubes etc which seens to work just fine. The other is what I would call a Colonial Boiler, a round pressure vessel inside a panel steel housing with a flat rectangular ceramic burner underneath the pressure vessel. I steamed the centre flue type first and thought it got up to the safety valve setting of about 45PSI fairly smartly although I did use hot water to speed things up. Then I lit up the Colonial type (again using hot water) expecting it to take a bit longer to get up to pressure. Instead it got up to a safety valve blow off pressure of 60PSI in about three minutes. As the pressure vessel seems to be about 8" x 3&1/2" inside the casing and does not have a flue up the centre it obviously holds a lot more water so one would think it would take some time to get up pressure but the performance was exceptionally good. The only reason I can think of is that the burner has such a large surface area that it puts more heat in to the water than a round burner puts in to the flue. It does have a number 16 jet so it must be using a fair amount of gas. Has anybody used this type of boiler and experienced this sort of performance? I am very pleased with what I got and it will be great for my stern wheeler plus it looks the part! Cheers, Ian.

[derekwarner_decoy]

Hi PD's......kiwimodeller .....Sandy Campbell [ACS] was a great manufacturing engineer & a beaut person to deal with

You may know I have an ACS VB2 vertical boiler and a number of ACS ancilliries  to go with this ...thanks Sandy

  .....Derek

[steamboatmodel]

Ian,
Can you post some photos of the "Colonial Boiler", does it have any tubes on the bottom of the main round pressure vessel ?
Regards,
Gerald.

[kiwimodeller]

Hi Gerald, thanks for that tip, I should have thought to look. It is difficult to see exactly as there is a bottom plate on the housing but looking through the little door in the end it is obvious that there are quite a few tubes protruding down from the pressure vessel. The main feed pipe also comes out of the steam valve, down the end and back under the boilerso it passes over the flame and dries the steam. No wonder it gets up steam so quickly with so much tubing directly in the flame. A good find methinks! Pictures attached I hope, cheers, Ian.

[steamboatmodel]

Without seeing in to the innards or under the skirt it is hard to tell, but if the tubes go cross ways across the width of the boiler it is probably a Scott boiler design. Sandy had sent me drawings for one with the caution that there was a lot of soldering involved and it would be a very fast steamer and require a feed pump with a eye on the sight glass. It looks like a great find.
Sandy's drawings are in the download section;
http://www.paddleducks.co.uk/smf/index.php?action=downloads;sa=view;down=285
They are listed as posted by Guest as are all his other downloads.
Does anyone know what happened with Sandy? I did have a email address for him other than the ACS one, but got no reply.
Regards,
Gerald.

[kiwimodeller]

Gerald, the drawing is very similar and the outside dimensions of the housing match up so I think it is likely that my one was built to this plan. The main difference is that the main steam pipe and the majority of the stop valve are inside the housing which makes it even tidier. Thanks for your help in tracking this down. I agree it is a pity we no longer have the benefit of Sandys wisdom. Regards Ian.