Engine house

[John Scott]

Evidently, the design and construction of the Sheepscot engine house will be the subject of keen attention!

I am attaching a diagram of an engine house design that includes an excellent form of smoke jack. Provision for good ventilation around the hot uptake is shown.

Looking at the photograph of the Wiscasset maintenance facilities that appears on page 221 of Two Foot to Tidewater, it can be seen that a rather more simple form of smoke jack was installed, there.

Given the existence of the fire safety issue, there will be a need for good judgement in the formulation of a smoke jack design for Sheepscot.

[Joe Fox]

Interesting design, although would make shedding water and snow a pain in the rear. Butterfly roof construction with valleys such as this has never been keen in New England.

Attached is a detailed drawing of how 90% of roundhouses are constructed in the U.S. with smoke jacks. https://www.google.com/search?q=roundhouse+smoke+jack&prmd=svin&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiP1qfb59LZAhWE1lMKHX8iBM0Q_AUIDCgD&biw=320&bih=406&dpr=1.5#imgrc=_KYFCS93jjBZ6M:&isa=y

Most roundhouse fires occured over night when the engines were banked. I am sure there will be some fire proofing done, but none that will effect the appearance of the building. I have been inside 5 steam shops with smoke jacks, all of which have the construction shown in the above link. Smoke jacks with no liners, and the roof butts up against it at the roof line. After enough use, there is enough soot build up on the smoke jack to act as a liner.

[Mike Fox]

I would like to see an airspace between the flue and the outer wall of any designed smokejack, along with proper spacing (treat these like a chimney) between it and wood framing. This may prevent a devastating fire someday, should the soot in the jack catch fire..

[Alex Harvilchuck]

I would like to see an airspace between the flue and the outer wall of any designed smokejack, along with proper spacing (treat these like a chimney) between it and wood framing. This may prevent a devastating fire someday, should the soot in the jack catch fire..

Plus line the smokejack with the Hardie Cement Board (comes in 4' x 8' sheets) and do the same with the door on the top. It's basically a chimney with a full-closing damper. Can use the Hardie trim to finish off the bottom and anywhere else one might think sparks could land.

I use a scrap of the Hardie board as a backer for the oxy-acetelyne torch when I solder large diameter copper pipes in situ. It is also resistant to a plasma torch - was in a pinch cutting in a tight spot.

[Joe Fox]

Smoke jacks are traditionally made from steel, so a liner is virtually pointless, but I am sure a spark deflector of some sort, or other fire proofing will be used inside. Roof beams are framed about 6-8" away from the smoke jack, with the roof sheathing butting up against the jack.

[John McNamara]

How about something like this (with a chimney cap added)?
https://www.ventingpipe.com/duravent-6dp-36ss-6-inner-diameter-duraplus-class-a-chimney-pipe-triple-wall-36-pipe-length/p2476626
-John M

[Joe Fox]

One steam operation uses this idea, and it works for them. Smoke jacks vary from 1.5 to 2 times larger than the smoke stack, and also have an elongated bottom to provide a larger area to "spot" the engine.