This locomotive had powered axles under it almost all the way from front to back. Nobody else built a diesel like that. Someone at Baldwin thought this was a good concept. Can anyone tell me what the rational was for doing it this way? I was just curious. I never saw one of these in service.
George
Only the middle eight axles were powered on a centipede. The first one was built as a Baldwin demonstrator which was sort of an early genset unit, which was supposed to have 8 750 HP transverse engine/generator modules (it only ever got four) for 6000 HP with the imposing model number DR-8-12-750/8 which indicated 8 powered axles (out of 12) with 8 750 HP engines. The prototype didn’t work out so the frame was re-used on the prototype for the production type DR-8-12-1500/2 which had a pair of 608SC engines for 3000 HP. Seaboard and NdeM got single unit versions (Seaboards’s would multiple with other makes - not common with Baldwin models) and PRR got two-unit drawbar-connected versions. None were particularly successful, though Seaboards an NdeMs’ had a fairly long life, improved after Baldwin developed the “Mexican Hat” piston (after its shape, not NdeM) to fix a chronic problem with turbo failures due to unburned fuel.
The rationale was based on 1930s electric locomotive design (think GG1) and on union contracts that did not allow treating MU consistes as a single locomotive. Changes in law and contracts would have done the centipedes in even without Baldwin diesels’ poor performance and high maintenance cost.
Labor contracts did not specifically mandate a crew for each diesel unit but management at the time did fear grievances over this issue. This was the rationale for the letter suffixes on booster units and one road number for four-unit FT sets.
It’s correct that only the middle eight axles on the centipedes were powered, however provisions wer made to power the other four axles for a “freight only” version. Both pilot and trailing truck had mounts for traction motors for a DR12-12-1500/2. Seaboard Air Line’s were retired in 1959 and 1960. Most of Pennsy’s were out of service in 1958 but actually not scrapped until 1962. NdeM 6400-6406 and 6409-6413 were rebuilt about this time. 6409 and 6412 would be gone by 1962, and all but three of the others were gone by 1967. 6401, 6402 and 6405 would serve NdeM until 1971. (Which leaves the tantalizing possibility that at one point, one locked knuckles with something as new as a GP38 or an SD40. Photos exist of them with C424s. NdeM had better luck with their units for serveral reasons. They had patient, persistent, highly capable and resourceful shop crews (which helped many an oddball locomotive survive). They also placed the units in service that played to their strengths. (Pennsy made the baffling decision–at one point–to attempt using them to shove cars over a classification hump–which gave them lots of practice at rerailing centipedes.) SAL’s were able to run with other units AFTER SAL rebuilt them with EMD-style electric throttles. (Baldwins came with a pneumatic throttle as standard equipment, which was why most could not MU with other builders’ units. This trait was a leading factor in dooming their locomotives to an early scrapping. Baldwin would later offer an electric throttle as an extra-cost option.) NdeM also ran trains suited to the use of a single centipede as power and also as manned head-end helpers between Saltillo and Carneros, both assignments that rendered their incompatibility with other units a moot point.
While there was a rampant fear among the railroads that the unions would demand a crew for each locomotive, there were no contracts that required this. Fortunately unions accepted the precedent set by traction companies (interurbans)
I’ve never seen any mention of the Centipede prototype being able to shut down and start up engines as needed. Without that feature it wasn’t a 1940’s era Genset.
Mexico’s Centipedes were rebuilt by Baldwin starting in 1953 which is when they received their new “Mexican hat” piston design and improved turbochargers that resolved most of their issues. They also lacked dynamic brakes which along with their inability to MU saw them gravitate to helper service where their high tractive effort could be put to good use and those drawbacks didn’t matter as much.
And while a large new locomotive order and a recession saw Pennsy’s Centipedes stored in 1958, many came out that Fall again and several stayed active into the 60’s. Retirement came in 1962 and some units were still active when that came.
Beyond reliability (Which was poor and saw Pennsy derate them), several significant mechanical issues, inability to MU with other power and lack of nose connections, and the lack of dyanamic braking, another significant issue with Pennsy’s were the drawbars which meant that only Juniata’s backshop could handle maintenance on them and roundhouses couldn’t accommodate them due to the length.
Retirement dates for SAL’s Centipedes show as 1961 for the 4500, 1957 for series 4501-4505, and 1961 for 4506-4513. For Mexico, I show two being unrebuilt and retired in 1954, two being retired 1961-1962, seven from 1964-1967, and the last three in 1971.
In fact, they could not longer MU at all (as built they could MU with other Baldwins through the rear. Also in theory they had 3200 hp available for traction after the rebuild. I knew NdeM’s and SAL’s didn’t have dynamic brakes–neither did PRR’s? Not a big surprise, absurd as it sounds, there was probably no room in them for dynamic brakes. They were used as road power also… which lead to double-headed centipedes (elephant-style) between Saltillo and Carneros as they held down some of the helper assignments on the 25 mile grade between those towns. It was as their ranks thinned further they would be seen primarily as helpers. I’m curious to know the fates of the first two NdeM centipedes to be scrapped, numbers 6408 and 6409. I have photo of a centipede in a head-on collision at an unspecified location (my guess being the line north of Mexico City, DF) and the damage looks serious enough it might have been scrapped–is this one of those two? Neither were rebuild by Baldwin in 1953, and this one is still in the as-delivered livery. (I’ve been operating under the assumption that the twelve rebuilt were repainted in the scarlet front scheme at time of rebuilding.)
I have different dates for the SAL units in different orders, though all mine show 1959 and 1960 dates. Our NdeM information matches. I had conflicting reports regarding PRR’s last time used, though have the 1962 retirement date from several sources. It was towards the middle of the 60s that NdeM’s started staying strictly between Saltillo and Carneros to serve as head-end helpers. As we’ve both noted, they went from 10 in 1964 to 3 by 1967. (It’s the ten still in service in 1964 that I have models of. 6400-6406, 6410, 6411, and 6413. Thank you Broadway Limited, even though they have the Pennsy carbody.)
Yeah, as far as I know none of them had dynamic brakes.
It created a dilemma for the Pennsylvania when the Fall traffic rush of 1958 hit and they were unexpectantly returned to service after being stored several months earlier. Maintenance had been neglecting their many brake shoes since there were so many and they were a pain to replace since a large diesel order that was planned to kill the last of steam during traffic rushes was expected to keep these from ever being needed again when a recession struck and reduced traffic requirements. So minimum work had been being undertaken in recent months.
But return they did and the brake shoes were in horrible shape due to their heavy usage due to the lack of dynamic brakes and subsequent neglect when it was thought they were done for soon. There’s first hand information in Trains Magazine of their reactivation and subsequent usage of some members into 1962 when they were retired so I think that’s reliable information. What I don’t know is just how many survived in active service into that final year.
My guess is that the photo you saw was indeed one of the two that was retired early in Mexico. I’ve never seen the reasons explained why they didn’t get rebuilt along with their sisters so crash damage makes perfect sense. I imagine the other unit also was seriously damaged and considered not worth rebuilding either via a wreck or a particularly bad fire.
My Centipede retirement dates come from this publication and were compiled by Kenneth L. Douglas with assistance from David H. Hamley. I can’t personally attest to their accuracy.
I had the impression from contemporary literature that the individual drive was intended for reliability in cases of road failure, and adjusting available power to train characteristics at the start of a given run. From what I understand, though, current designs of genset are not designed to fully start and stop engines based on actual load, although there are controls allowing separate loading/idling, so the comparison is not as dismissible as it may appear at first. That functionality would be relatively simple to add to a Centipede, as you’d only need to interrupt the throttle rack opening and generator field on a selctable-individual-engine basis. (This might well be electrical rather than pneumatic, because no proportionality is required, but you would need some sort of dashpot to prevent excessively quick throttle response when individual engines were cut in with the locomotive at high speed or load.) I would NOT expect any early expectation of MUing 6000 HP locomotives together in the early '40s, even if Baldwin weren’t working off analogy with single-locomotive-headed consists a la steam. If MU were to be combined with individual control over 8 engines per unit … well, actually, the EMD ‘digital’ logic system (with three ‘bit states’) would have worked because at least one engine per locomotive would have to stay running at all times, so you could easily ‘isolate’ in pairs, triples, etc. even without addressable switches and cables for each individual engine in multiple units…
These things would NOT be used in switching, so very little benefit in full demand-based on-the-fly startup/shutdown. Even if the coolant loops were interconnectable to keep a chosen set of engines hot, an
And since we have single engine locomotives that are still called “Gensets”, you don’t even need multiple engines to be called one. So I misspoke.
I think most though when they think of a Genset, they think of multiple small engines and the ability for those to matched to the job.
You know, to be honest I had always thought of ‘gensets’ as being multiple-engined locomotives, and what I was saying about '40s-era ‘gensets’ did explicitly presume that – so Leo does not need to qualify his reply merely on that basis. This post of Leo’s brings up a (possibly) important semantic issue:
Is a given locomotive a “genset” if it takes advantage of small packaged engine-generator sets, or just because it uses a small high-speed engine/generator set in place of a larger or purpose-built diesel-electric powerplant? I believe most ‘genset’ locomotives with only one “genset” in them are actually hybrids, like the Green Goat, that use a small onboard engine-powered generator for charging and/or peak power assist. Those are probably best considered not as ‘genset’ locomotives, but assisted battery locomotives, or hybrid locomotives.
(Situation might be – not really, but semantically – complicated because there are so many standalone generator units with 567s and 645s in them… ;-} )
Technically it is possible to build a ‘genset’ chassis but populate it with only one genset unit to start. It would also be possible to take the 567 out of a unit like a Geep or F unit and replace it with a genset, for example to make a dinner-train locomotive EPA compliant or more economical to keep in service. But neither of these changes the fundamental assumption that a ‘genset’ locomotive is designed around the assumption that there are multiple engines, and the output power of the engine is ‘scaled’ by controlling
The original Baldwin Centipede demonstrator (described by me as a sort of 1940’s era Genset) really was more like 8 750 HP locomotives on the same chassis. I can’t locate the article that explained this, but it appears that the intent was to have each engine pod power one axle, but I’m sure the idea of starting and stopping individual engines never even ocurred to Baldwin engineers. It would probably have been nearly impossible with Baldwin’s pneumatic controls. I think the idea was that the smaller 750 HP engines, of a design similar to the rugged VO engine used in switchers, would be easier to maintain than larger, tubocharged engines like the 608SCs used in the later versions. I think it says a lot that only four of the engine pods were built. The plumbing connections to add or remove them must have been pretty messy.
BLW 6000 was less a demonstrator and more of a testbed for Max Essl’s concept of multiple small engine-generator sets. Only four engines were actually installed in the testbed since a World War was occurring at the same time, which caused various limitations and shortages.
The article describing this monstrosity is in the January 1963 TRAINS.
Since I can’t (yet) get into my DVD Trains collection – were the engines that were actually originally installed the 408s (as I suspect) or the 300/12LV V-12s? [Edited note: Only 408s were built for installation in the carbody: four production, and one spare (that was later installed when needed to replace one that had failed). Intriguingly enough – there were wood mockups, probably weighted for balance, installed in the other four bay areas…]
Also: Does the article go into the specific weaknesses of the 408 design that led to discontinuation? They must have been severe, as BLW’s whole postwar strategy was based on big, slow horsepower, and when they went back to high-speed power it was not with either gensets or American engines, but with German technology and Mekydro drive… [Edited note: Westing says it was generator field modulation, and then overall cost of the complex locomotive, that were the problems, not something intrinsic and insoluble with the V-8 700/750hp engines]
(Of course, this is leaving out the potentially very interesting ‘untold’ history of the free-piston locomotive powerplant, which I think was Baldwin’s perceived ‘ace in the hole’ in just this period… and while that IS a legitimate ‘Centipede’-related topic, I think from the design information that has survived that the chassis had gone to span-bolstered trucks by the end of the '40s.)
What I have read is that the idea about the modular units was to allow spares to replace ones with problems at.a.drop table thereby increasing availability of the engine and minimize down time. don’t forget these were still pretty early in diesel history and before standardization. Fairbanks Morse didn’t succeed either in the long term on spite of a very successful marine history
I have now hacked my copy to the point I can read the relevant issues (1962 and 1982).
Westing: Jan 1963 pp.38-42
Brown: May 1982 pp.38-45 (and then two more Centipede articles)
Essl patents:
2249628 (Jul 15 1941)
2299420 (Oct 20 1941)
and the one most specific to 6000, issued after the locomotive was built
2317849 (Apr 27 1943)
According to Westing (who would know!) the stated objectives for the modular drive, as perceived at the time, were (1) minimal reduction of power upon failure of one (or more) engines, and (2) ease of servicing. This had two parts: the engines were easy to remove, and spare engines could easily and quickly be installed (making it unnecessary to work on engines while confined in a carbody). A key part of this was the installation of the radiators and coolers in a ‘modular’ section of the locomotive roof.
Proof of the second part was rather dramatically illustrated when an engine went out during testing on the Reading, and the engine was swapped out for module #5 in “less than 20 minutes” (Westing, p.39)
As it turns out, I was wrong; although the engines were lined up to be close to the right side, there was an aisle up the left as well as between modules that made it relatively easy to get to the engines. Unlike the British Leader, the asymmetrical mass distribution of the offset engines was ‘counterweighted’ in the location of the radiators and coolers to keep the engine laterally balanced.
It would appear that the reason for the initial failures of this locomotive were related to excessive excitation loading. By the time that was fixed, the ‘bean counters’ had come to the realization that the locomotive was never going to be a particularly inexpensive proposition vis-a-vis a cheap bridge-truss carbody sitting on pin-guided trucks … and a principal advantage of the design, large HP in a single unit, was rendered irrelevant by agree
The free piston was Lima’s ace in the hole, not Baldwin’s.
It was a Hamilton project that Lima embraced after acquiring them for their diesel technology. But it hadn’t progressed far enough along to produce a prototype installation on a locomotive when the firm unexpectantly merged with Baldwin with Lima’s promising designs & research projects quickly killed off like work on a free piston gasifier locomotive.
Even though Lima’s projects showed great promise and orders for existing designs were quickly growing with the company set to surpass Baldwin’s sales that year when the merger the board secretly arranged shocked the entire company, Baldwin factions reigned supreme with the Lima plant and staff assigned to heavy construction equipment manufacturing. It was the nail in the coffin for that research project, their entire line of locomotives, and their many innovations that Baldwin engineers almost universally ignored and failed to incorporate into their own designs.
Lima’s designs were more advanced, showed much promise,and many felt at the time were better locomotives. Yet everything except the parts business was quickly killed off (And many Lima orders were outright cancelled rather than substituting an equivalent Baldwin design), Even at the end of 1963 well over a decade after the last locomotive rolled out of the erecting hall and well into the diesel replacement age with railroads standardizing and moving away from older minority makes, 164 of their 174 locomotives were still
It certainly was Baldwin’s after the merger. I repeat that one reason for retaining the 606-8 style slow-speed engines involved a belief that the free-piston gasifier was going to be the future of high-horsepower-at-lower-cost locomotives. And much of the reason for Baldwin acquiring LH had to be the gasifier development… it certainly wasn’t anything to do with steam engines; it certainly wasn’t anything to do with Lima-Hamilton diesel-electrics; the cranes and such were useful, but I think not a major reason for merger.
Lima ‘embraced’ Hamilton for the gasifier, not the diesels. It’s, I think, mostly circumstantial that Hamilton offered a local supplier for engines. Engines that were just as limited as Alco 539s in context.
Several of the key patents for gasifier application to locomotives at Baldwin date as late as 1959.
The thing that killed the gasifier was very likely noise, and I think probably pulse noise in the intake tracts, not the exha
Lima-Hamilton was set to surpass Baldwin in sales the year of the merger despite the long head start that Baldwin had. Furthermore, what locomotives that they did produce enjoyed long lives and surpassed many of their competitors from even the more successful firms in longevity despite their small number and many going to larger railroads (Which isn’t a recipe for longevity such as the non Class 1 origins of many surviving Baldwins can attest to).
Beyond Lima’s quality control and attention to detail, their designs were innovative in many ways. The use of a dry sump lubrication system, many steps being taken that eased the inspection process for many components compared to the competitors at the time, interchangeable exhaust and intake valves, gear driven engine auxillaries, water cooled exhaust manifolds, I believe the first use of an intercooler on an American locomotive, electric traction motor blowers (Which reduced the clutter that competitors had with their jackshafts, gear boxes, and V-belts cluttering things up under the hoods of contemporary switchers), stress relieved bolster and fuel tank weldments to correct a problem competitors were having, running all cabling through conduits (Something Baldwin’s oil leakers with their exposed wiring would’ve been wise to adopt), and hollow center castings and truck bolsters for the cool traction motor air to be routed through to name many of them. Several of which would become industry standards.
And like I said, many outsta
What a delight it is to hear from someone so knowledgeable about these subjects!
There is no doubt that Lima QC and interest in detail design was higher for diesels, just as it was for steam locomotives.
My suspicion has been that Lima remained a proponent of steam for heavy mainline use very late (Long Compression being touted 1949 and perhaps even into 1950) and this had something to do with the bias toward reliable switcher HP. If there are records of a Lima attempt at a multiple-unit freight or passenger locomotive, something to match, I would dearly love to see them, because I have not seen anything of the kind. Road switchers were probably good, but only sold to one customer (NYC), and for dedicated commuter service at that. Seems to me that Lima might have concentrated their early diesel-electric designing on what makes a good switcher – and yes, I concur readily that they nailed it well – but not seen widespread road dieselization as a niche until… too late.
I do have to wonder why Baldwin didn’t adopt LH construction methods, just as I wonder why they ignored the lessons from EMD’s designs. I was more than a little surprised to find that the C&O M1 turbine effort was a Baldwin in-house design, and NOT an adaptation of Loewy’s Triplex or PRR’s V1 (right down to construction being kept secret from key PRR people!) and so the technical foibles of those locomotives can be squarely placed at Baldwin’s door, too. I personally think there is no excuse for wiring something in a way that produces untraceable ground faults – let alone encourages them. Much less excuse when your merger partner not only understands this, but has proper solutions in place…
[quote]
Beyond Lima’s quality control and attention to detail, their desig
this why this forum exceeds all expectations all the time[:P]