Canadian Railroads > Dual Air Hoses on CP Rail AC units: What are they for?

I've often noticed on the later AC units CP uses, particularity GEs in this regard, that they have dual full sized airhoses. It's not a Passenger Train setup with a main trainline hose and a smaller hose for the main reservoir. It's also not the Control Hoses.

I've also noticed that some of CP Rail's Bethgons have dual air-hoses. Why would one need a secondary trainline hose on a train?

DMIR's Ore hoppers also have them.

Parker Boots
Metairie, LA



Edited 4 time(s). Last edit at 07/21/14 09:30 by SD45-2.

CP's unit coal trains in BC have holding brakes.

KG

Because the trucks on 24 foot ore cars are so close to the end of the cars, the wheels are not tucked in entirely under the frames, and thus are so closely spaced between cars that it is dangerous and difficult to do the air between cars. So, the DM&IR (now CN) mounts the air lines high, above the coupler. To accommodate connections to such cars, many locomotives (and also cabooses when they were used) have two sets of hoses, one below and one above the coupler. These connections are for standard operation of the automatic air.

In addition, these cars are equipped with a second "straight air" system - locomotives and cars have an additional brake hose connection for this straight air system

SD45-2 Wrote:
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> I've often noticed on the later AC units CP uses,
> particularity GEs in this regard, that they have
> dual full sized airhoses. It's not a Passenger
> Train setup with a main trainline hose and a
> smaller hose for the main reservoir. It's also not
> the Control Hoses.
>
> I've also noticed that some of CP Rail's Bethgons
> have dual air-hoses. Why would one need a
> secondary trainline hose on a train?
>
> DMIR's Ore hoppers also have them.

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Thanks, but why do they have a second "straight air" line? Insurance? Faster Charging times?

Parker Boots
Metairie, LA

SD45-2 Wrote:
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> Thanks, but why do they have a second "straight
> air" line? Insurance? Faster Charging times?


An ore train of 130 cars (120-132 being pretty standard) is only 3100 feet long. Straight air can be applied and released quickly, and graduated release is available. The automatic system remains fully charged and available for emergencies. The grades down to the Lake Superior docks in Duluth and Two Harbors are each several miles of 2.18% and 3%, respectively.

One is for English cars, one is for French speaking cars......

Most CP units have dual air hoses even SD 40s account rotory dump cars in coal service

MJplanner Wrote:
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> Most CP units have dual air hoses even SD 40s
> account rotory dump cars in coal service


The correct answer for current operation.

In the 1970's, most CP locomotives had the brake pipe, and the "signal line". In passenger service, this smaller air hose transmitted whistle signals between car vestibules and the operating cab allowing the conductor to communicate with the engineer before the advent of radio. This "signal line" carried air straight from the main reservoir at 140 psi.

The "signal line" was also used to supply air to operate many types of work equipment, such as wedge plows, Jordan spreaders, flangers and "Difco" air dump cars.

Initially, CP's "bathtub" coal gons had a "grade holding brake", a straight air brake which applied pressure to the brake shoes on the first 24 cars behind the lead locomotives, replacing the need to apply retainers. This feature was abandoned by the mid-1980's.

The Missabe Road Historical Society's publication ORE EXTRA had a very nice article a few years back on the "Straight Air" system Missabe used (and CN still uses).

Officially known as the Orinoco Straight Air System, it allows the Engineer to maintain a set on the cars while recharging the automatic air. Think of it as being able to variably set and release retainers on the whole train from the cab.

The article appeared in Vol. 21 No 2 of the ORE EXTRA. If you can't pick it up at a swap or from a friend, it is still available from the society as part of a four-issue set (all of Volume 21) for $25.00. Go to www.missabe.com.

NZ

It is worth mentioning that the DMIR's Orinoco Straight air and the Straight air on the CP units are different systems...