It is a box and contained the products of combustion but that was not what it was called. What happened in the flue below that needed containing and taming occasionally?
Stanley Challenger Graham
Stanley's View
scg1936 at talktalk.net
"Beware of certitude" (Jimmy Reid)
The floggings will continue until morale improves!
Old age isn't for cissies!
You have it Tom! With alternate hand firing of the furnaces you could get a circumstance where one fire was burning clean and the other was making green smoke. When that happened there could be explosions in the back of the boiler flue. This is why there was always a mid feather wall in the flue to divide the two flows but the explosion could happen in the sole flue then. The explosion boxes relieved the pressure because the heavy cast iron lids could lift.
Next one?
Stanley Challenger Graham
Stanley's View
scg1936 at talktalk.net
"Beware of certitude" (Jimmy Reid)
The floggings will continue until morale improves!
Old age isn't for cissies!
Compared with an overshot waterwheel the direction of rotation is more efficient. It rotates in the same direction as the water flow whereas the overshot wheel rotates against the flow.
Nullius in verba: On the word of no one (Motto of the Royal Society)