steve24944 Today when UP runs the Heritage Fleet, they have the power cars to provide steam and electricity to the passanger cars. Back in the heyday of steam, how did the Locomotive provide electricity ? Steam Engines have the steam generator on top of the boiler to make electricity for the locomotive, but that's not large enough to provide electric power for the whole train. Or is it?
Today when UP runs the Heritage Fleet, they have the power cars to provide steam and electricity to the passanger cars. Back in the heyday of steam, how did the Locomotive provide electricity ? Steam Engines have the steam generator on top of the boiler to make electricity for the locomotive, but that's not large enough to provide electric power for the whole train. Or is it?
In some cases there was a turbine generator set mounted on the tender or baggage car that provided power for car lighting. Connection to the rest of the train would be through a three wire system with loop back to equalize voltage drop. This was mainly found on suburban trains which needed to be as light as practical for acceleration. Axle driven generators meant a lot of weight for the generators and batteries, not to mention the drag. Typical unit size was ~20kW and steam source was the steam heating line.
Some of the early electric lighting installations would use batteries that were recharged at the terminals - batteries were swapped out in some cases. This progressed to axle driven generators keeping the batteries charged. Electric lighting became a lot more practical when the tungsten lamps replaced carbon filament lamps.
A/C equipped cars often had on board engines, typically propane fueled, to provide power for the compressor and would often provide power for lighting and ventilation.
As others have commented on, head end power for A/C appeared on some of the early streamliners, but was dropped for later trains for compatibilty reasons (Amtrak has now set the statndard). A funny note was that the UP found that HEP with electric resistance heating used less fuel than steam heat.
Thank you for that lenghty reply. Good information.
Steve
steve24944Do the UP Heritage Fleet Cars still have the wheel generated power?
Amtrak has fairly recently made any form of wheel-driven generator, specifically including any kind of Spicer drive, illegal for any car intended to run in one of its consists. That would preclude any UP car operating on an Amtrak move, or as part of any charter. This has become relatively less significant since Anderson deprecated the business of pulling any non-Amtrak cars, but still argues very strongly for the use of Amtrak-compatible HEP on UP's dedicated equipment ... and for the choice of equipment used to run behind Heritage Steam excursions. You may note that extended layovers are not a problem (as they would certainly become for axle-drive powered cars!) once you have the kind of large generating capacity that a couple of the UP cars do (I believe Howard Fogg is an extraordinary example).
As you may have figured out, some special care has to be taken with private cars that are fully Amtrak-compliant for HEP but also have their own self-contained generators. The two systems have to be kept electrically isolated for some of the same reason 'islanding' in distributed grid power is constrained.
Keep in mind that in the earlier days, there was comparatively little need for electricity on trains: stoves or steam provided the heat, and some patent form of gas (there are some descriptions in White's book on the American passenger car, which you should find and read). Early electric lighting often involved a dynamo, in or around the baggage car; these were usually primitively small by modern standards. Storage batteries that had satisfactory capacity without great additional weight used ... interesting ... chemistries and might produce noxious gases in use (see the Daniell cell for one example that was touted for traction applications in the 1860s but, I wonder why, failed to live up to the promise...)
In the heavyweight era you begin to see self-contained operation, with each car having some sort of wheel-driven dynamo (the Spicer drive came along a bit later) and/or on-car batteries. The great thing that emerges here is the advent of air conditioning: even approaches like ATSF's steam-ejector systems required fairly lavish electrical power to run, but it would have made little sense to install a full turboelectric generator for the required train's capacity, plus electrical busses large enough for any car to lead and not suffer excessive resistance heating, so the idea of self-contained power 'by the car' with no coordination survived until very late in the day.
Now as you might imagine, there would be trouble if you had, say, 18 heavyweight Pullmans in the train, and they were all set to have the generators clutch in and begin generating power as soon as the cars began to move, then scale the output properly as the physical devices gained rotational speed. What is essentially 'free power from the locomotive' for a couple of cars turns into an enormous amount of aggregate drag on the drawbar, and 'down low' in the horsepower curve where a high-wheeled locomotive is, near starting, that drag accentuates any tendency to slip (although it does temper the worst aspect of surge)
So what was done was to stagger the starting and excitation so that cars would come progressively 'on' at various speeds. You can see the effect graphically (pun intended) in one of the illustrations in Kiefer's 1947 report on motive power.
Now we come to streamlining, where even early 'motor trains' depended absolutely on air conditioning to be livable, and had many other features that used electricity. In Clessie Cummins' book is an illustration of one of the early Zephyrs which has a virtual 'power room' full of little Cummins gensets to provide the necessary power for a lightweight train; the situation got even more extreme toward the end of the '40s as the new mass orders of competing lightweight cars vied to outdo each other's comforts and conveniences ... still presumably powered by steam or early diesels that wouldn't have expensive whole-train generation, so still a combination of batteries, on-board engine-driven generators of a variety of sizes and fuels, and the aforementioned Spicer axle-drives (which provided a sealed unit with relatively low unsprung mass and good maintenance characteristics for higher-speed trains of the era).
Let me note here that the fuel used for the engine-driven generators could vary, but flammability and exhaust products could restrict where such cars could operate or be allowed to stand. Those driven by compressed gas or LPG, for example, weren't allowed to traverse some tunnels, or even to have fuel in them.
The 'better' solution, of course, is HEP, which puts the generator in some dedicated place 'up front' and only carries electrical cabling down the car (converting it in voltage and type when needed). Early versions of this, as noted, were usually comparatively low-voltage;some things, like the Budd 'tubular train' of the 1950s, needed a separate 'power car' to provide all the amps to run the various systems.
Amtrak in order to replace steam heat as well as provide high levels of air conditioning and various lighting etc. went all the way up to 440, but had to spend an enormous amount of money in the systems, plugs, and dedicated power to implement it. They built or bought a number of power cars to allow the 'new' equipment to run behind older locomotives not set up for compatible HEP, some of which were converted from locomotives (I believe one fairly extreme example was the LIRR cab cars converted from FAs, at least some of which retained their 12-244s for HEP purposes for a while)
Dedicated fleets of commuter equipment that are paid for with public money can have similar HEP arrangements; a few of the Chicagoans here are familiar with arrangements that provided dynamos on steam locomotives to supply ample lighting for dark winters without slowing down acceleration, including for a brief while the use of steam to pull bilevel sealed-window gallery equipment.
There are threads in RyPN about various tourist railroads who implement "HEP" with little more than a set of glorified extension cords and gas emergency-type generators. Makes connecting to 'shore power' relatively possible, too.
Older cars were 32v probably with a belt drive. Newer cars were 64v then 110v with a spicer drive, a clutch and a motor generator. These cars had EM air conditioning and a large set of batteries and could be plugged in at coachyards or stations. If the electricity failed cars could be trainlined to one another but you had to be careful because all 3 systems had the same recepticle for trainlining so you had to be sure the cars were the same voltage. Some cars also had an "enginator" in place of the generator which supplied electricity for that car only.
HEP means Head End Power. Electricity for lights and HVAC is provided by a generator on the locomotive either turned by the prime mover or its own smaller engine.
OK So ... HEP operation means, that cars do not provide their own power ?
steve24944So ..... Do the UP Heritage Fleet Cars still have the wheel generated power ? The UP power cars provide Steam and Electricity ? Steve
Do the UP Heritage Fleet Cars still have the wheel generated power ? The UP power cars provide Steam and Electricity ?
UP's cars are set up for HEP opeation - the Amtrak standard.
Never too old to have a happy childhood!
So .....
I don't know about the others, but late in the steam era the Jersey Central had steam-powered generators mounted on the locomotive tenders to provide electricity for the passenger cars. It replaced the older car-mounted generator and battery system.
Yes, the lightweight cars were built with generators. I believe that 32 volts was the standard supply.
Johnny
CSSHEGEWISCH The locomotive provided steam for heat and air conditioning but electricity was provided by wheel-driven generators and batteries on each car.
The locomotive provided steam for heat and air conditioning but electricity was provided by wheel-driven generators and batteries on each car.
OK Thanks
With the mix of various cars and cars from different decades, did all cars have wheel generated power ? When did the railroads start building passenger cars with this power supply ? Was the wheel generated power still a part of the new streamline passenger trains that were built after the war that had the new Diesel Passenger Locomotives.
Today everybody ( me included ) is thrilled to see Big Boy and that beautiful passanger train tour the country. I went up to Evanston WY, and Ogden UT back in May.
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