What are all these connexions for?

[melmerby]

Hi all

While watching VRF cam and a multi-headed Amtrak service with 2x Genesis & 3x Charger, the camera dallied on the couplings.

 

Why so many cables & pipes?

 

[Allegheny1600]

Whilst I’m not an expert, may I hazard a guess?

 

1. multiple loco control.

2. coach power supplies.

3. transducer connections - these tell “base” where each individual vehicle is on the network and if connected, can all say the same thing!

4. engine management controls - “talking” to each other. Different to 1. in that each locos engine may perform differently during the run. ?

 

What I do know is that modern US locos are very sophisticated, have a lot of engine management systems and communications systems. Wherever Amtraks base is, will know all about each locos performance and whether anything needs changing en route. Plus the same again for each coach!

All that needs a lot of cables.

 

Happy for any further input or corrections though.

[melmerby]

On 05/10/2022 at 12:20, Allegheny1600 said:

What I do know is that modern US locos are very sophisticated

Freight locos seem equally well provided with interconnexions.

Some I know are for traction current so that excess TE can be passed to a road slug for better pulling power. FEC do this regularly.

 

I've also seen BNSF locos piloting an Amtrak train, with cables connected, more than once on Virtual railfan

[russ p]

33 minutes ago, melmerby said:

Freight locos seem equally well provided with interconnexions.

Some I know are for traction current so that excess TE can be passed to a road slug for better pulling power. FEC do this regularly.

 

I've also seen BNSF locos piloting an Amtrak train, with cables connected, more than once on Virtual railfan

 

So modern amtrack stuff is still fitter with AAR multi working.  Do US locos have air pipes for what we know as straight air brake?

[barkingdigger]

15 hours ago, russ p said:

Do US locos have air pipes for what we know as straight air brake?

 

The air pipe is the bigger black one directly under the couplers - all US trains use them from end to end.

[dave1905]

The black hose in the center is the automatic air brake train line (all engines).

 

The three black hoses on either side are the engine brake hoses (almost all engines).

 

The big red cables are multiple unit control (MU-electrical control connections between consisted engines) and the head end power supply (lights and power in the trailing cars).  Almost all engines have a MU cable connection but only passenger engines have a power supply cable.

 

The small cables on the sides are most likely signal, auxillary power and control lines to the passenger cars (only passenger engines).

Edited October 7, 2022 by dave1905

[russ p]

1 hour ago, dave1905 said:

The black hose in the center is the automatic air brake train line (all engines).

 

The three black hoses on either side are the engine brake hoses (almost all engines).

 

The big red cables are multiple unit control (MU-electrical control connections between consisted engines) and the head end power supply (lights and power in the trailing cars).  Almost all engines have a MU cable connection but only passenger engines have a power supply cable.

 

The small cables on the sides are most likely signal, auxillary power and control lines to the passenger cars (only passenger engines).

 

Do you know what the 3 hoses are for. If one is straight air and I would guess another main reservoir can't think what third may be

[dave1905]

Don't know what you mean by "straight air".  

They are main reservoir, independent application and release and independent actuating.  

Main reservoir connects the main reservoirs on all the engines (which supply air to the whole air brake system on the train.)

Application and release apply and release the engine brakes.

Actuating allows the independent brakes to be released while the train brakes are applied.

[russ p]

On 08/10/2022 at 03:09, dave1905 said:

Don't know what you mean by "straight air".  

They are main reservoir, independent application and release and independent actuating.  

Main reservoir connects the main reservoirs on all the engines (which supply air to the whole air brake system on the train.)

Application and release apply and release the engine brakes.

Actuating allows the independent brakes to be released while the train brakes are applied.

 

Cheers Dave, you have answered my question.  In the UK we call independent brake straight air as its a direct application of air into the locos brake cylinders. 

I did think that on US diesels the independent brake applied brakes on all locos coupled together.  I didn't realise that this requires  two pipes. Our locos have no facility to apply independent brakes on other locos other than the lead , I was surprised 68/88 didn't have this facility as straight air/ independent brake is applied electronically 

[dave1905]

When the automatic air brake applies, it also applies the independent.  The "2nd" hose is used to release the independent without releasing the automatic.  

[russ p]

8 hours ago, dave1905 said:

When the automatic air brake applies, it also applies the independent.  The "2nd" hose is used to release the independent without releasing the 

 

Cheers Dave,  is that what you guys call bail off?

[dave1905]

 

10 hours ago, russ p said:

is that what you guys call bail off?

 

Yes