What is wrong with this locomotive?

Trains do have regenerative braking, meaning that their electric motors generate electricity to slow down the train. But that electricity is purposely wasted in the braking resistors.

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Well, I don't know about water. The diesels I'm familiar with use antifreeze. Why would diesels, big or small, use pure water?? For a variety of reasons, corrosion just one among them.

The main reason, afaict, is like trucks: cold-weather starting of diesel fuel. The only reason not to leave the engine running would be electric heat for, well, everything fuel related, which might burn more energy than letting the engine idle.

Why especially gentle?? I figgered it was pure economy of function.

*Passenger cars* with electric motors almost universally use regenerative braking. But it's pointless in diesel locomotives. If a 6,000 hp diesel is hauling a consist of, say, 100 cars, and NONE of those cars have electric motors, ergo no capacity for regen brakes, what purpose does the regen braking in the locomotive itself serve? Itsa drop in a bucket.

The diesels I'm familiar with in fact do *not* have regen brakes, and there is no real reason for ANY diesel to use regenerative brakes, unless it is shuttling around consists considerably lighter than itself. And then, in this case, the speeds are so low that regen braking is ineffective. Regen braking needs about 10 mph min, and that's often the max allowable speed in switching/train yards. Below 20 mph, regen braking is minorly effective, perhaps the "break-even" point between regen and friction.

I'm not saying there are no diesels with regen brakes. I'm saying it's pretty pointless for diesels to have them, AND not all of them do. It would be understandable, and no slight of design, if in fact few of them have regen brakes. The diesels that would benefit from regen brakes would be diesels doing a lot of solo travel, or hauling short consists at high-ish speeds. But both of these functions violate the intended purpose of diesel locomotives, and thus are likely not common scenarios.

As I mentioned, what diesel locomotives DO have are hyooge air compressors -- for about 100 psi or so trainline air pressure -- to activate the friction brakes of every single car (heh, every axle) in the consist, clear down to the caboose.

There are two ways to activate trainline brakes. One is to have huge air tanks in the locomotive supply all the trainline air for braking, right to the brake pistons. The other more efficient way is to have each car with its own reserve tank, and the air from the diesel locomotive activates electromagnetic valves in each car, which release a specific car's stored air to that car's brakes. Thus, the air from the locomotive is more of an "air signal" than the actual "brake air" or "piston air" itself -- that air is supplied by the local reserve tanks.

On electric passengar cars, each car (or every other car in a "married pair") has its own supply tank AND compressor, with the operating engineer controlling the trainline "signal air", which activates each passengar car's electromagnetic valve between the brake piston and the supply/reserve airtanks. Signal air is stored in its own tank. And these cars also have regen braking as well, which is ALSO controlled by the trainline air signal! Highspeed braking in electric passenger cars is nearly 100% dynamic or regen braking, with the friction brakes kicking in at under 20 mph.

Altho some ultra modern systems may dispense with air signalling in favor of electric signalling, new cars being delivered to the NYC subway system are ALL outfitted with the trainline air signalling system -- for a variety of reasons, also having to do with tripping the emergency brakes of trains. This too could be accomplished electrically, but to this day, air is used.

Freight consists do not generally have the dynamic/friction crossover, they are all friction.

I guess I missed out on the OP, and it's hard to follow now, but the pix I see is normal. It is a 4400 HP, GE AC44CWCTE. It has some extra-ordinary roof equipment, some of which is the standard dynamic braking resistors, and some looks like extra cooling but I'm not sure.

Here's a series of pix of 5720 running:

Take care.

Brian Lawson

Note in the last picture of the set (November 2012) the engine had mismatched side panels on it. - on the opposite side shown in the "what's wrong" picture.