The B&M Berkshires with Coffin FWH had a smaller diameter stack mounted on the heater just forward of the smokebox stack. I would appreciate some understanding.
Thanks to all who contribute.
selector The B&M Berkshires with Coffin FWH had a smaller diameter stack mounted on the heater just forward of the smokebox stack. I would appreciate some understanding. Thanks to all who contribute.
The Coffin type feed water heater used exhaust steam to heat feed water contained in piping in an arch shape either inside or forward of the smokebox.
Some of the steam condenses to water and is drained off at both sides of the "arch" at the bottom. The stack allows steam not condensed to vent at the top, just forward of the main stack.
Other types of heater mix the exhaust steam with the feed water (Like the Worthington S and SA) and do not need a stack.
In theory there is a risk of contaminating the feed water with lubricant from the valves and cylinders with mixing type feed heaters.
I have a reproduction Lionel 700E scale J1e Hudson, and it has a small additional stack since 5340 had a Coffin feed water heater.
Peter
Thanks for your response, Peter. The question was posed on another forum, and I am not familiar with the Coffin FWH, and have never noticed, or seen, the smaller stack such as the ones on the B&M Berks.
-Crandell
...it is the throttle. Bradford type.
Vents on FWHs are small pipes. Engines with a trailing truck booster engines will exhaust through a medium size pipe just ahead of the smokestack. This second plume of steam can be seen on videos of the C&O 614 when the booster is operating.
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Also courtesy of Big Jim (from the wonderful NWHS collection) -- here is a diagram of what is inside the smokebox of a locomotive equipped with a Bradford front-end throttle:
http://www.nwhs.org/archivesdb/detail.php?ID=26522
Feedwater-heater vents would be small in diameter. Other designs of closed heater had them, too, but most people don't 'see' them in typical pictures of standing locomotives. The situation is very different when the locomotives are in operation at speed, particularly in cold weather where even small mass flows become clearly visible. See the many examples here, now that you know what to look for:
M636CI have a reproduction Lionel 700E scale J1e Hudson, and it has a small additional stack since 5340 had a Coffin feed water heater.
Peter, you know better. I believe 5340 was one of those B&A J2s (which in part accounted for why a Coffin heater was installed... the town of the bean and the cod, you know...)
Thanks, Overmod. I am always open to learning something about steam locos, and your help is especially valuable to me.
You are welcome!
Aww....shucks!!! I failed to notice the split in the post, maybe confusing the pictures and the individual posts. Please accept my apologies, Big Jim...I missed that it was you. I do very much appreciate your contribution, and have relayed your information to the other forum.
Dang.....
Overmod M636C I have a reproduction Lionel 700E scale J1e Hudson, and it has a small additional stack since 5340 had a Coffin feed water heater. Peter, you know better. I believe 5340 was one of those B&A J2s (which in part accounted for why a Coffin heater was installed... the town of the bean and the cod, you know...)
M636C I have a reproduction Lionel 700E scale J1e Hudson, and it has a small additional stack since 5340 had a Coffin feed water heater.
BigJim M636C I have a reproduction Lionel 700E scale J1e Hudson, and it has a small additional stack since 5340 had a Coffin feed water heater. Peter,That is the exhaust stack for the booster engine, not anything for a FWH.
Peter,That is the exhaust stack for the booster engine, not anything for a FWH.
I'm quite prepared to believe that, but not all J1 Hudsons had the stack when new although they appear to have boosters fitted. Many j1d have no small stack and a booster. On the other hand, a post war photo of a J1e shows that stack missing, although there is still a steam pipe past the firebox.
Where did the booster exhaust on locomotives built without the small stack?
Those Coffin feedwater heaters are aptly named, the externally mounted ones anyway.
Those B&M locomotives are downright creepy looking with those units hanging on the smokebox fronts like shrouds. Very funereal.
Just my opinion.
M636CI'm quite prepared to believe that,
Sometimes it was placed behind the smokestack.
M636CWhere did the booster exhaust on locomotives built without the small stack?
Someone could probably write an article on all the different methods and theories regarding routing of booster exhaust. The issue can be complicated by the same argument regarding the 'secondary' escape pipe on the Triplexes: do you, or don't you, want to use the heat and mass contribution from the booster exhaust to make draft?
The 'typical' installation for the original boosters (and auxiliary locomotives; I'll be agnostic about suppliers) discusses providing a separate nozzle in the stack arrangement for the booster piping, which I always thought would involve incorporation in the blower ring through a separate manifold. Very, very early this was changed (although the 'reasons' were not carefully enumerated) to the typical arrangement bringing the exhaust up to just behind the stack. Meanwhile, on a J1 with the typical Elesco, the booster exhaust could be brought up past the superheater header and shell 'invisibly', at the cost of a bit of additional pipe, and routed ahead of the stack where it would interfere less with the fireman's ability to 'read the exhaust'. I suspect this routing might change if the locomotive later received a Worthington FWH ... probably to the 'standard' location behind the stack with external plumbing, but you might consult photos.
Note the arrangement in the drawing of the J3 that has been posted. This was comparatively late practice on a locomotive class that could be expected to use a high-speed booster right to the end of its nominal speed range in some cases.
Keep in mind that these boosters do not have any more variable cutoff than a typical donkey engine (fixed at 75% or 50% at the shop, with a clever implementation of Weiss/starting ports in the latter case by necking the piston valve at the admission edge), and are actuated without a modulatable throttle (the late example on SLSF 1351 still has only a simple air valve to apply the booster; everything else is 'automated') The effect of randomly dumping the mass flow expended by such a thing, even if using a multiple-speed arrangement to reduce the horror at higher nominal road speeds, into a front end carefully optimized to work efficiently over a large range of speeds and load with best 'automatic action', is easily left to the imagination.
Scroll down to Fig 2. to see one way to route the exhaust: http://www.icsarchive.org/icsarchive-org/bb/ics_bb_506_section_2355_type_c-2_locomotive_booster.pdf.
Something that I found quite odd while researching the booster engine on the NYC Hudson was the lack of information in Gerbracht's "Know Thy Hudsons" book. His only mention of the booster engine had to do about when they were removed!
BigJimSomething that I found quite odd while researching the booster engine on the NYC Hudson was the lack of information in Gerbracht's "Know Thy Hudsons" book. His only mention of the booster engine had to do about when they were removed!
Especially weird since boosters were an explicit NYC invention, and I suspect the story of how they came to be adopted and then presumably carefully used on Hudsons would be interesting and complex history in its own right.
I have semi-purposefully put off buying a copy of 'Know Thy Niagaras' for somewhat similar reasons regarding my dread of how he's handled the events during the locomotive's development, particularly regarding the C1a up to early 1945. Sometimes historians miss or ignore things that HPS people think are more important...
OvermodI have semi-purposefully put off buying a copy of 'Know Thy Niagaras'...
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