Jonathan-
Thank you for your thoughtful treatise...I really enjoyed reading it and it
makes sense to me. The Burlington was (putting it politely) a Frugal line,
and spending money even to save money is difficult for the truly tight
fisted.....
As an example, in reading the Aurora Beacon notes from Joe Douda there was a
column that reported that the deadline for equipping cars with Air Brakes
was fast approaching and that the Burlington had determined it was more
economical to build new cars than retrofit old ones. Certainly factors like
fitness for further service under changing load demands weighed heavily in
their decision, not just the economic cost of conversion vs. new.
Thanks,
Charlie
> -----Original Message-----
> From: jonathanharris@e...
> [mailto:jonathanharris@e...]
> Sent: Thursday, March 14, 2002 4:25 PM
> To: BRHSlist@yahoogroups.com
> Subject: [BRHSlist] Use of Feedwater Heaters on the Burlington
>
>
> John and Scott,
>
> Many thanks for your postings. It sounds like you both know a lot more
> about steam engines than I do. I apologize for taking so long
> to respond
> and even more for the monstrous length of what follows
> (anyone who just
> wants "the bottom line," please scroll down to the last 2
> paragraphs; those
> of you who love plumbing, grab a lunch and read on).
>
> After thinking about it, I still am not persuaded that the
> most important
> benefit of feedwater heaters was fuel or water savings. I do
> get what you
> are saying. I'm sure it's the majority view; in fact I think
> it's exactly
> the conventional wisdom against which I was arguing in my
> last posting.
> Don't misunderstand me; I agree with all your facts. The
> increased thermal
> efficiency FWHs provide is undeniable; and as you rightly
> point out, that
> translates into savings of fuel and to some extent water -- which then
> allows trains to operate with fewer servicing stops, thus
> faster and more
> efficiently. But I suspect that's not the whole story, or
> maybe even the
> most interesting part of it.
>
> If you were to ask me, for example, why I flipped on the
> light switch in a
> room at 3:00 a.m., I wouldn't say it was because an
> incandescent bulb can
> illuminate the dark space at low cost. Factually true though
> that may be,
> it wouldn't tell you anything very useful about my motives.
> Somewhat the
> same problem with citing themal efficiency or fuel savings as
> the reason
> for using feedwater heaters. It begs the question of WHY the
> Burlington or
> any railroad used them as they did (when, where, and on which
> locomotives?).
>
> John anticipates this objection when he cautions that the
> expected savings
> had to be greater than the capital cost of installing, plus
> the ongoing
> cost of maintaining the FWH system. And theoretically he is
> right, but that
> raises the tricky question of how to measure savings. In
> reality, a lot of
> considerations probably came into play when deciding when to
> use this or
> any improved technology on new or existing engines. Some
> important costs
> and benefits may have been perfectly real but less tangible and
> quantifiable than, say, the price of coal consumed. If the
> addition of FWHs
> helped reduce the need for double-heading, for instance, or
> of purchasing
> new power, or if they just helped trains keep to faster, more
> competitive
> schedules, they might be considered worthwhile even when they
> cost more to
> install and maintain than they saved in fuel.
>
> It's often the case that people (and companies) make economic
> decisions for
> reasons other than the obvious, stated ones (economists worry
> about such
> questions all the time, and some even have won Nobel Prizes
> for figuring
> out the "reasons behind the reasons" for people's economic
> behavior). In
> the case of steam technology, the choice of which extra
> appliances to add
> to new or existing engines, like any management decision,
> undoubtedly took
> into consideration information that was coming in from all over the
> corporate structure -- from the accounting department at one
> end to the
> shop foremen and engine crews at the other. Only by looking
> at the overall
> pattern of how the railroad actually used -- or did not use
> -- feedwater
> heaters can we get a fair sense of what they really thought
> were their most
> important benefits.
>
> The 1935 List of Assignments in Corbin and Kerka (Steam
> Locomotives of the
> Burlington Route, p. 292) gives us the chance to do just
> that. As Scott
> notes, Corbin and Kerka's 1935 list has a wealth of information on how
> engines were equipped with various steam technologies, and
> geographically
> where those engines were used. It thus provides a snapshot of the
> Burlington's decision-making process at one point in time --
> a very useful
> snapshot, too, since it was a time when steam power was used in almost
> every "niche" all over the system.
>
> So which engines had feedwater heaters? Well, most obviously,
> newer, larger
> engines -- just what you would expect. Big engines used the
> most fuel and
> water, and they probably ran up the most miles too, so the
> savings would be
> greatest, right? True, but bear in mind that feedwater
> heaters were not
> included on new engines until the mid-1920s (the T-2 mallets
> are a special
> case; they were built in 1910 with a split boiler, which
> provided a kind of
> internal feedwater heating system). None of the mikados or
> Santa Fe types
> built before 1925 had FWHs when delivered. None of the
> Pacifics did, nor
> did the original B-1s. I think the B-1As (1925) may have been
> the first to
> have them included by the manufacturer, and everything built
> afterwards --
> the M-4s S-4s and O-5s -- had them as standard equipment. On all other
> classes, however, they were retrofitted during the 1920s and 1930s.
>
> Or not -- raising the question of which engines were upgraded with
> feedwater heaters, and why?
>
> Again, as you would predict, larger engines tended to be
> upgraded, smaller
> engines not. The cut-off point for freight engines was about
> the 2-8-2.
> Most mikados had received feedwater heaters by the time of
> the 1935 list,
> but a significant number (almost one third, in fact) had not,
> and what is
> more interesting, many never would. Almost everything larger
> than a 2-8-2
> was FWH-equipped by that time, though there were a few
> outstanding M1s or
> M2s still using injectors only (interestingly, most of those
> are listed as
> stored unserviceable, which tells me they were awaiting major
> shopping and
> were about to have FWHs added; or they were about to be retired). No
> smaller freight engines are listed as having FWHs. No consolidations,
> prairies, ten wheelers or moguls. And no switchers.
>
> For passenger engines, the cut-off point was the Pacific.
> Smaller passenger
> engines -- e.g., Atlantics, ten wheelers, and prairies -- used only
> injectors (I have seen at least one photo of a prairie with a
> Worthington,
> and there may have been a few other exceptions, but this was the broad
> pattern). The overwhelming majority of Pacifics (over 90%)
> were equipped
> with FWHs by 1935. All heavy Pacifics, Mountains and Hudsons had them.
>
> What does this pattern tell us? That more fuel is to be saved
> with larger
> engines? Yes, but it's far from a perfect correlation. Does
> an O-3 drag
> freight engine working tonnage at a tractive effort of 60,000
> lbs really
> use less fuel and water than a light passenger engine like an S-1A
> (tractive effort 31,000 lbs.) pulling a 5-car train? I'd
> doubt it. Yet all
> the S-1As were equipped with feedwater heaters, while a large
> number of O3s
> (as well as some O2s and many O1s) weren't. Indeed, if we include the
> "out-of-service" engines, the percentage of all 4-6-2s
> without feedwater
> heaters (8%) was lower than the percentage of 2-8-2s (30%) or
> even 2-10-2s
> (13%) equipped with only injectors.
>
> Let's think about this from a different angle for a moment.
> As John and
> Scott have explained, feedwater heaters save energy and thus
> fuel by using
> waste heat (e.g., in the smokebox) to preheat water before it
> is admitted
> to the boiler (some models recapture exhaust steam, thereby conserving
> water as well as heat). Sounds great -- so then, why wouldn't a
> conscientious engine crew use such a wonderful device all the
> time? Why use
> the injectors at all? Well, consider the following scenario.
> You've just
> crested a grade. You stop working steam, your fire is hot, and boiler
> pressure is rising. What do you do? You're probably not going
> to throw open
> the throttle again, especially if you're about to head
> downgrade. You could
> just let the pop valve go, but THAT would waste steam, water,
> and fuel. You
> could do some housecleaning and blow down the boiler. But why
> not inject a
> little cold water and use that excess energy to heat it up, thereby
> lowering the pressure a bit and conserving the water and energy you've
> already invested? Here, using the injectors rather than the
> FWH would be
> the better choice -- or so it was explained to me by one
> retired engineer.
>
> All right then, so when do you benefit most from using
> preheated feedwater?
> In exactly the opposite situations: i.e., where you need to
> work steam --
> accelerating a heavy train, running a heavy train upgrade, or
> any other
> time when a large volume of high-pressure steam must be
> replenished quickly
> and/or constantly. And that, I would argue, is why FWHs
> appear to have been
> so much more essential on the Burlington's light Pacifics
> than on its heavy
> mikados. Because they really helped these relatively
> small-boilered engines
> in accelerating heavyweight passenger trains and running them
> at sustained
> high speeds, especially over the undulating topography of the western
> lines.
>
> As often is the case, it is the exceptions which prove the
> rule. Let us ask
> which engines in a particular class did NOT receive feedwater heaters.
> (Note: these figures are based on quick counts; my numbers
> may be off by a
> few either way, but they're roughly correct.) In the case of the 112
> Pacifics on the 1935 List of Assignments, the roster shows
> only 9 without
> feedwater heaters: 4 unmodernized S-1s and 5 unmodernized
> S-2s; all are on
> the Chicago Division. Why? Because these were not mainline or even
> branchline passenger engines, but commuter engines, a service
> which did not
> demand sustained steaming. (Commuter service is notoriously hard on
> boilers. These engines were probably also considered near the
> end of their
> useful service, and most were gone within 5 years.)
>
> The case of the mikados is equally instructive. By 1935 most
> engines in
> classes O-1A through O-4 had received feedwater heaters. But
> out of 336
> total mikados on the roster, 101 still were using only
> injectors. To break
> these numbers down, there were 46 out of 48 O-1s and 14 out
> of 148 O-1As
> with injectors only. All 15 O-4s had acquired feedwater
> heaters by 1935.
> And all 52 O-2As had them, as well; the latter presumably
> were installed
> when the O-2s were upgraded, since all 13 remaining
> unmodified O-2s on the
> list still had only injectors (and seven of those engines were out of
> service). Among the 60 O-3s, only 32 had FWHs, slightly more
> than half. We
> can add, parenthetically, that some of these engines did
> receive FWHs at a
> later date. But others did not, and as noted in my earlier
> posting, when
> the Coffin-equipped O-3s lost their FWHs, they reverted to the use of
> injectors only (and Gerald Edgar is correct; there were four
> such engines).
>
> What accounts for this pattern? The case of the O-1s and O-1As seems
> clearest. Those O-1As which had FWHs were probably regular
> road engines
> used in freight service, while the unmodified O1s with
> injectors only were
> being used as switchers or in transfer service. I'm sure this is not a
> perfect correlation, but I'll bet it's close. Note, for instance, that
> almost a quarter of those unmodified O-1s were assigned to
> the Beardstown
> Division, where (thanks in part to John's superb monograph on
> the Q's coal
> fields operations) we know that many were employed as mine
> switchers. And I
> suspect that most of the other unmodified O-1s (in Denver,
> Chicago, and on
> the St. Joseph Div.) were also engaged in switching or pinger service,
> neither of which demands much sustained steaming. It's worth
> reiterating
> here that no dedicated class of Burlington switch engines
> used feedwater
> heaters -- not even the T-1s used in hump yard service during the
> mid-1920s, nor the F-2s into which they were rebuilt (with
> their 61,000 lb
> tractive effort), nor the USRA 0-8-0s.
>
> The case the O-2s and O-3s is a bit more complex (these two
> classes were
> virtually identical in many respects, the main difference
> being that the
> O-3s were designed with greater thermal efficiencies,
> including firebox
> arches, combustion chambers, improved superheaters, etc.). By
> the time of
> the 1935 roster, many of the older O-2s had been or were
> being converted
> into O-2As with the addition of similar energy-saving technologies,
> including in all cases feedwater heaters. But as noted
> earlier, many O-3s
> continued to operate their whole lives with only injectors.
> What was going
> on here? Well, these were drag freight engines, designed to haul heavy
> trains at slow speed. To do their job, they relied more on
> tractive effort
> and momentum than sustained steaming, except where grades
> were encountered
> (and they were not known to perform particularly well in such
> conditions).
> If you check the List of Assignments, you will notice that 5
> out of the 6
> injector-only O-2s remaining in active service, as well as
> all of the O-3s
> without feedwater heaters, were on the Lines East, where
> grades were fewer
> and gentler. By contrast, almost all of the Lines West O-2s
> (i.e., O-2As)
> and O-3s HAD been equipped with FWHs.
>
> As for the O-4s (all FWH-equipped by 1935), they too were Lines West
> engines, and as such regularly had to move tonnage up grades.
>
> If exceptions can prove the rule, then exceptions to those exceptions
> sometimes can be equally revealing. For instance, I just said
> all O-4s had
> feedwater heaters. Well, yes and no. The parent company's O-4s all had
> them, but the FW&D's E-4A2s, which were identical USRA heavy
> 2-8-2s, did
> NOT. As I suggested in my last posting, I suspect this was
> because they
> could operate well enough with just injectors over their
> essentially level
> trackage. And only two of the otherwise unmodified O-1s DID
> have feedwater
> heaters -- one assigned to Denver, one to Casper. But there is another
> notable group of similar engines -- namely, the C&S's E-4A1s
> -- shown as
> leased to the Beardstown Division in '35. ALL these were equipped with
> Elesco FWHs. And remember that those engines, in their
> original service,
> had been expected to contended with the grades along Colorado's Front
> Ranges.
>
> To sum it up, feedwater heaters DO save fuel and sometimes
> water. But like
> most modern steam technologies, they do so marginally; they prove
> economical in some cases and not others. And the decision of
> whether to use
> them probably balances many factors. On the Burlington, FWHs
> seem to have
> made the most critical difference in situations where they wanted to
> improve an engine's capacity for sustained steaming -- in
> passenger engines
> pulling increasingly heavy trains during the 1920s and '30s,
> in freight
> engines where speed was required, and wherever the heaviest
> freight trains
> had to contend with significant grades.
>
> That's how the overall pattern looks to me, anyway. But as I
> conceded up
> front, the two of you probably know a great deal more about
> this stuff than
> I do. So please feel free to point out where the train of my
> reasoning has
> hit the derail.
>
> Jonathan
>
>
>
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