Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Bonjour Maxwell,
Nice plant indeed !
I have several steam plants with coupled pumps and I like having small boilers as soon as the pump is efficient because the burner needs to heat a smaller volume of water, example :

Besides this, I have a very small experience of coal with my Yarrow boiler which I tested only on a table. What I noticed is that coal heats hard and is very difficult to keep the fire going correctly
 
Based on this, I think it is very difficult to manage one boiler in a boat, evoking two is just not realistic.

Your boiler seems quite efficient, without any question of money, installing a larger one would be more weight and, as you would have to constantly look after the fire ot the water level, I would kindly suggest you to keep your plant as is, install a bypass valve if not already done and, during your navigation, have regular glances on the water level and the fire to adjust them if needed.

Besides this, I think that a steam bower is more than useful, it is mandatory, does the exhaust pipe that I see going in the chemney has an impact on the fire ?