Kentucky & Tennessee #106 Wrecked and Totaled

superheater · **Joined:** Sun Aug 22, 2004 11:54 pm **Posts:** 2605

E.B. Levin wrote:

My experience with the early SW/NW's up to SW1200 is that the hand brake is rigged to operate the clasp brake rigging on both wheels of the #4 axle. From memory it is typically rigged through the cab floor passing through two sheave wheels and then acts on a cross bar that acts on the two rear facing duplex cylinder pistons.

Some issues that I have encountered when investigating locomotives that have rolled out when the hand brake has been "applied" generally fall into these buckets:

1. Brake rigging frozen or defective.
2. Extended piston travel on cylinders the hand brake acts upon.
3. Hand brake chain twisted/bound. Intermediate rigging frozen.
4. Lack of proper mechanical advantage on account wrong hand brake mechanism installed.
4A. Lack of physical strength by train crew member.
5. Rare instance of applying hand brake with hot shoes and wheels then cold weather release.

All the above will give the crew a false sense of proper hand brake application at the wheel or lever.

All except #5 can generally be fleshed out with independent release and application of power.

EBL

Could No. 2 be fleshed out with a proper pre-op onspection , a 99 cent Harbor Freight tape measure, a knowledge of proper piston travel and how to adjust.

I'm not sure this works on a unit of this type, I was mostly trained on passenger equipment with P and UC.

E.B. Levin · **Posted:** Tue Feb 18, 2025 9:52 am

Supe:

Piston travel is something that should be looked at during daily inspection.

We always used to stencil the truck side frame with maximum piston travel. 4-1/2" for duplex switcher cylinders and 6-1/2" for standard cylinders. Typically it is adjusted with a slide and pin type slack adjuster. The old style used a threaded arrangement with a detent.

Thinking about this a little more we did run into some hand brake holding issues on GP units that were converted from clasp brake with cast iron shoe's ( J1 45 lb. independent BC pressure) to single shoe composition (J1.6-16 72 lb. independent BC pressure). They would hold but would roll when power was applied in 1st notch. The units that were converted to composition shoes but retained clasp brake (J84B 36 lb. independent BC pressure) held OK.

Hand brakes on later model SW's with flexicoils only applied to the #2R wheel. Same with MP's

EBL

jayrod · **Posted:** Tue Feb 18, 2025 11:11 am

Eric - Thanks for the explanations.