Steam & Excursion > Coffin Feedwater Heaters

Been curious about these things for a while, and was wondering if anyone could point me to a reference on how they worked and why they were shaped the way they were.

The place I've seen them most often is on B&M Berkshires, where the Coffin feedwater heater formed a "cobra hood" in front of the smokebox. Santa Fe and SP picked up some of these oddities second-hand, and Santa Fe also experimented with a Coffin on their own 2-8-2 #4007. Googling around the web turns up references to B&M 3713, preserved and under restoration at Steamtown, having an "embedded Coffin" behind the smokebox front. How common were these devices? Was "Coffin" the name of the company that built them, ala Worthington or Elesco?

Evan_Werkema Wrote:
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> Been curious about these things for a while, and
> was wondering if anyone could point me to a
> reference on how they worked and why they were
> shaped the way they were.
>
> The place I've seen them most often is on B&M
> Berkshires, where the Coffin feedwater heater
> formed a "cobra hood" in front of the smokebox.
> Santa Fe and SP picked up some of these oddities
> second-hand, and Santa Fe also experimented with a
> Coffin on their own 2-8-2 #4007. Googling around
> the web turns up references to B&M 3713,
> preserved and under restoration at Steamtown,
> having an "embedded Coffin" behind the smokebox
> front.

There were two basic types of feedwater heaters.

In the open type, such as a Worthington, feedwater was sprayed directly into a chamber of exhaust steam, condensing the steam and raising the water temperature. Both a cold water pump and a hot water pump were required. Worthington heaters such as used on SP had the mixing chamber and both pumps all in one assembly (invariably on the left side), whereas the more common Worthington Type S had two separate pumps (usually the cold water pump on the left and the hot water pump on the left or on the pilot) and the mixing chamber above the smokebox.

In a closed type, small diameter piping containing the feedwater was run thru a chamber of exhaust steam, and the water did not actually contact the steam. These chambers were larger, such as the Coffin and Elesco, but only required one pump.

>How common were these devices?

Quite common. Retrofits usually placed the chamber in an arch in front of the smokebox door, but original construction usually placed it out of sight behind the door, so they were really more common than appearances would make you believe, and you really have to look for the piping connections to detect their presence.

Was
> "Coffin" the name of the company that built them,
> ala Worthington or Elesco?

Yes.

Evan_Werkema Wrote:
-------------------------------------------------------
> Been curious about these things for a while, and
> was wondering if anyone could point me to a
> reference on how they worked and why they were
> shaped the way they were.

Well, there are only two types of feedwater heaters, open (or direct) and closed (or indirect). "Open" heaters inject some of the exhaust steam into the water being fed into the boiler, heating it up. "Closed" heaters are simply heat exchangers, like the radiator / heater coil / condensor on your car.

The Coffin heater was a closed type. They were shaped that way because they were intended to be installed inside the smokebox like an Elesco or the closed Worthington types.


> How common were these devices? Was
> "Coffin" the name of the company that built them,
> ala Worthington or Elesco?

Yes. And they weren't the most popular brand, but they weren't total rarities. CN & B&M used them, and NYC Hudsons and Mohawks got them. (Not sure about the Niagaras.)

JAC

MTM,

Again you've come to the rescue, explaining the mysterious technology that fascinates us. There are relatively few folks today who understand the total mechanics of "Coal & water in, motion out".

Thanks

John G

MTMEngineer Wrote:
-------------------------------------------------------
> Evan_Werkema Wrote:
> --------------------------------------------------
> -----
> > Been curious about these things for a while,
> and
> > was wondering if anyone could point me to a
> > reference on how they worked and why they
> were
> > shaped the way they were.
> >
> > The place I've seen them most often is on
> B&M
> > Berkshires, where the Coffin feedwater
> heater
> > formed a "cobra hood" in front of the
> smokebox.
> > Santa Fe and SP picked up some of these
> oddities
> > second-hand, and Santa Fe also experimented
> with a
> > Coffin on their own 2-8-2 #4007. Googling
> around
> > the web turns up references to B&M 3713,
> > preserved and under restoration at
> Steamtown,
> > having an "embedded Coffin" behind the
> smokebox
> > front.
>
> There were two basic types of feedwater heaters.
>
>
> In the open type, such as a Worthington, feedwater
> was sprayed directly into a chamber of exhaust
> steam, condensing the steam and raising the water
> temperature. Both a cold water pump and a hot
> water pump were required. Worthington heaters
> such as used on SP had the mixing chamber and both
> pumps all in one assembly (invariably on the left
> side), whereas the more common Worthington Type S
> had two separate pumps (usually the cold water
> pump on the left and the hot water pump on the
> left or on the pilot) and the mixing chamber above
> the smokebox.
>
> In a closed type, small diameter piping containing
> the feedwater was run thru a chamber of exhaust
> steam, and the water did not actually contact the
> steam. These chambers were larger, such as the
> Coffin and Elesco, but only required one pump.
>
> >How common were these devices?
>
> Quite common. Retrofits usually placed the
> chamber in an arch in front of the smokebox door,
> but original construction usually placed it out of
> sight behind the door, so they were really more
> common than appearances would make you believe,
> and you really have to look for the piping
> connections to detect their presence.
>
> Was
> > "Coffin" the name of the company that built
> them,
> > ala Worthington or Elesco?
>
> Yes.
>

Many of the UP 5000 class 2-10-2s used Coffin feedwater systems, also. They were not uncommon.

johnacraft Wrote:

> The Coffin heater was a closed type. They were
> shaped that way because they were intended to be
> installed inside the smokebox like an Elesco or
> the closed Worthington types.

Elescos were installed inside the smokebox? I guess I had assumed that the Elesco feedwater heater was the cylindrical object CB&Q often mounted externally above the smokebox and Santa Fe mounted below the smokebox (usually). Was that only part of the device, or did some roads mount that cylindrical object in the smokebox itself?

Some engines had the Elesco feedwater heater recessed into the smokebox. Good examples are the NYC J-1 4-6-4s. I don't know of any that had completely hidden Elesco feedwater heaters.

Also, please note that you see a Coffin system today. Go to Cheyenne, Wyoming, and get permission to visit the UP roundhouse. UP 2-10-2 #5511 not only has the Coffin feedwater heater recessed into the smokebox, but also this engine has the only surviving example of Young valve gear. A picture was posted in Trainorders not too long ago.

Some NYC J-1 Hudsons and most (all?) of the Boston & Albany J-2's had Coffin heaters built into the smokebox, as did the B&A A-1c Berkshires.

WRT Elesco's being built into the smokebox, they were on the NYC Hudsons that had them, as well as many of the later subclasses of L-2 Mohawks. The L-3b Mohawks (Lima built) had a particularly ungainly application of the Elesco, built into, yet mostly atop, the smokebox, giving an odd, flat-faced, beetle-browed look.

The Niagaras all had Worthington SA's, I think.

I wonder why the B&M Berks had the Coffin heater hung off the front of the smokebox, since they were built new with them. Might have been to avoid having to modify the interior arrangement of the smokebox of the Lima design (originally equipped with an Elesco bundle on the B&A and IC) to accommodate the Coffin.

Walt

Evan_Werkema Wrote:
-------------------------------------------------------
> johnacraft Wrote:
> Elescos were installed inside the smokebox? I
> guess I had assumed that the Elesco feedwater
> heater was the cylindrical object CB&Q often
> mounted externally above the smokebox and Santa Fe
> mounted below the smokebox (usually). Was that
> only part of the device, or did some roads mount
> that cylindrical object in the smokebox itself?

Elesco heaters could be mounted out in front of the smokebox (T&P 610, for example), or recessed to a lesser or greater degree into the smokebox itself (Southern Railway 1401). If the smokebox diameter was big enough, the entire bundle could be recessed far enough so that very little of it was visible.

I suppose in theory one could even mount an Elesco somewhere other than on the smokebox, though the plumbing would get more complicated.

JAC

Also, before I forget, Milwaukee 2-6-6-2s had Coffins on the boiler front like the B&M T-1s, as did Denver and Salt Lake 2-8-2s.

> > johnacraft Wrote:

> I suppose in theory one could even mount an Elesco
> somewhere other than on the smokebox, though the
> plumbing would get more complicated.
>
> JAC

I believe the Santa Fe mounted the Elesco "bundle" on the pilot deck on many engines such as Mikados, Pacifics and 2-10-2's, no?

Walt

Seems like most, if not all, of the big Santa Fe steam engines of the 1920s had the Elesco feedwater heater on the pilot deck.

A quick Google search of "Coffin feedwater" turns up many more examples, such as WP 2-8-8-2s and an SR Ps-4.

There were two kinds of Elesco feedwater heaters. The most common type being the round bundle mounted on top such as T&P and many D&RGW engines. Even some D&RGW elescos were on the pilot deck and exclusively that way on Santa Fe with only a couple of exceptions. The 2nd style of elesco was the one most commonly seen on Rio Grande M-68 4=8-4's numbered 1800-1804. They also appeared on some Central of Ga. engines. ONly a small portion of them was exposed in the top of the smokebox and it looked like two bundles joined together.

I am surprised that so many "open" type of heaters were used, because the exhaust steam would have cylinder oil in it and it would have to be seperated out before injection of the heated water into the boiler.

Sorry I got to this one so late. Man, there were a lot of feedwater heater system variations, as so many of you pointed out on the NYC. The Elescos made those Berks look brutish, and I guess that's why the Central buried them in the Hudsons. If you see a photo of a Hudson (and it will be a photo as all were cut up) that has no hint of an Elesco sticking out the sides of the smokebox, nor an obvious Worthington on top of the smokebox, chances are it has a Coffin inside the smokebox. I, too, could not figure out why the B&M chose to mount theirs the way they did. Ugly.

CB&Q had at least one O3 class 2-8-2 that carried an external Coffin at one time. This engine was easily identified after the unit was removed as it retained its centered headlight, an unusual feature for older CB&Q power.

Silver Sky

Frisco was a big user of the Coffin FWH. All of their later, heavier motive power (4-6-4s,4-8-2s and 4-8-4s) as well as the 4200 class mikes were so equipped.

Frisco1522 Wrote:
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> Frisco was a big user of the Coffin FWH. All of
> their later, heavier motive power (4-6-4s,4-8-2s
> and 4-8-4s) as well as the 4200 class mikes were
> so equipped.

Even the 1522? It's pretty hard to see any Coffin-related appurtenances around the smokebox in the photos I've been able to find. BTW, what does the Coffin feedwater pump look like, and where's it located?

Walt

wlankenau Wrote:
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> Frisco1522 Wrote:
> --------------------------------------------------
> -----
> BTW, what
> does the Coffin feedwater pump look like, and
> where's it located?
>
> Walt
>
>
>
Small turbo powered centrifugal pump, not much larger than a non-lifting injector, mounted close to the ground below the left side of the cab.

Oooops, I should have qualified the 4-8-2 statement. The 4300-4310 and 4400-4422 class mountains were equipped with Coffin FWH. None of the 1500 class mountains had feedwater heaters. Sorry.
Frisco seemed like they were not too particular which side the pump was mounted on.

wlankenau Wrote:
-------------------------------------------------------
> >
>I wonder why the B&M Berks had the Coffin
> heater hung off the front of the smokebox, since
> they were built new with them. Might have been to
> avoid having to modify the interior arrangement of
> the smokebox of the Lima design (originally
> equipped with an Elesco bundle on the B&A and
> IC) to accommodate the Coffin.

Clearance issues at Hoosac Tunnel in Western MA on B&M's Line to Mechanicville, NY. A
T-1 Berk with an Elesco Bundle type feedwater heater mounted in the conventional position ala B&A's Berks would have been in trouble there. I guess nobody thought of mounting it on the pilot like Santa Fe did on some engines. I'm not sure why B&M could not have had the T-1 Coffins installed in the smokebox like their R-1a,b,c Mountains (the R1d's had Wothington SA's.) and their P-4a and b Pacifics.

Regards,

rcall31060
Bob Callahan
Monticello, IN
rmcallahan@hotmail.com