Chicago Metra Cab-car whistle question.

[Bob-Fryml]

Most Chicago Metra commuter trains run push-pull with a diesel locomotive on one end, and a control compartment equipped cab-car on the other.

Compressed air from the locomotive main reservoir is piped through an electro-pneumatic valve controlled by the engineer, and the compressed air escaping from that valve is used to power the locomotive horn.

QUESTION:  What is the source of compressed air that powers the horn on the cab car?  Do the gallery cars have hoses and pipes that transfer locomotive main reservoir directly to the control compartment of the cab car?  Or do the horns somehow tap off of the brake pipe without appreciably lowering brake pipe air pressure? 

 

[zardoz]

The cab-cars have their own 130psi main reservoir drums, which is supplied by the locomotive through direct connection via main reservoir hoses throughout the train. The air system functions about the same in the cab-car as it does on the locomotive.

[Paul_D_North_Jr]

Any other locomotive-type connections between the cars, like the other 3 hoses usually seen on MU-ed units ?  Obviously, the train-lined air brake; the Main Reservoir connecting/ equalizing hose; the 27-pin jumper cable; and whatever is needed for the Head-End Power and communciations, etc. between the cars.  But what about the other 2 hoses - the Independent Actuating (ACT) for Applications and the Brake Cylinder Release hoses ?  I would think perhaps not, but then there would be no way to control the locomotive's Independent Brake from the cab car, if desired - that's not one of the functions on the standard 27-pin electrical jumper - but I don't really know . . .

See "US Loco MU Control" at: http://www.railway-technical.com/us-musp.shtml 

Thanks in advance.

- Paul North.

[CSSHEGEWISCH]

I read somewhere that the engineer can't use the independent brake when the train is being pushed and controlled from the cab coach.  This may be true for all suburban push-pull operations.  I have not seen the additional air lines needed to control the independent brake on any of the gallery cars on my ride to and from work (Metra Southwest).

[mudekk01]

You are correct; no independent brake from the cab car.

[zardoz]

mudekk01

You are correct; no independent brake from the cab car.

There is, however, something akin to the independent: it's called the parking brake. This is an on/off type, although the older ones (on the non-stainless old CNW cars) could vary the application pressure by manually holding the valve in various positions between the 'off' and 'on' positions (I'm not sure about the new ones--they arrived shortly after I left).

There are no other air connections between the cab-car and the locomotive other than the brake pipe and main reservoir hoses. Just the jumper cable and the HEP cables.

[uphogger]

Furthermore, there is no electro-pneumatic valve controlling the horn on the cab cars.  It's all straight air and the two controls are either a standard handle (retrofitted a couple of years back) or the original foot pedal (the one I got used to and prefer).  There IS an electro-pneumatic valve for the horn on the F40PHM-2's (the Winnebagos).  We currently have the 210 and that thing is like dating your sister: something just ain't right about it.

[DanM64]

I've always wondered a couple things about Metra systems. On the regular F40's, there's a red button on a plate where the dynamic brake handle used to be. What is the button for?

Also as far as the braking system goes- There's 3 brake guauges instead of 2, the 3rd one having a black needle marked Suppression Pipe and a red one marked Application Pipe. What are those for?

Thanks!