Reports out of Stearns, Kentucky are that the Kentucky and Tennessee Railway's (Big South Fork Scenic Railway) SW9 #106 somehow got away from its crew and ran away unmanned down the railroads steep gradient and leaped a curve embedding itself into the side of the mountain.

Pictures coming out show the entire fireman's side of the locomotive has been destroyed and its been reported that the wreck was severe enough that the prime mover and the generator actually broke their mounts. It would appear the loco is totaled.

Engine was running light and no other equipment was involved.

Good thing that they recently acquired a locomotive from U.S. Sugar.

Several people asked me, so here is the update. It is locomotive 310.

USSC 310 is a GP11, a rebuilt Electro-Motive GP9, that was originally built in December 1957 (#23830, FN 5553-31) as Illinois Central #9330. It became Illinois Central Gulf #9330 in August 1972. It was rebuilt (GP11) as #8710 in August 1979 and became Illinois Central #8710 during February 1988. It was sold and became South Central Florida Express #9024 and then became U. S. Sugar #310.


Bart

Photo sourced from public Facebook group (not mine).

How difficult will it be for them to rerail it and bring it back to their shops?

[redacted]

https://www.trains.com/trn/news-reviews ... ws-report/
"If a mechanical issue rendered the locomotive incapable of generating enough air for its independent air brakes, the crew would rely on its handbrake and wheel chocks as alternatives. But temperatures were near zero on the day of the derailment and frost build up on the rail could have made it difficult for the wheel chocks to remain effective, according to the source. Moreover, an SW9’s handbrake only clamps down on a single brake shoe and isn’t meant to keep a locomotive stationary on steep grades. The source says the extremely cold weather could have also contributed to the locomotive’s mechanical issues."

Reading between the lines, it would appear that perhaps the air compressor and/or a valve in the brake system became unhappy with the frigid air and froze up, resulting in a lack of air brakes. (had this happen with a GE 80 ton that had an air activated forward/reverse switch on a cold day, worked twice and then froze solid). Reading the story posted on trains renders my initial statement above pointless as is appears that the entire locomotive shut down and ceased forward motion, thus causing the lack of air to hold the locomotive air brakes on. The handbrake did not (or could not) hold and the skates slid. In my experience, many skates can be ineffective on equipment with brake shoes or slack adjusters in front of the wheel as such things tend to catch the skate and push it before the wheel is fully on it (a lesson learned on narrow gauge cars with body hung brake beams)

No fun

Jason Midyette

Was it skates or chocks? I'd be leery of skates on anything other than nearly level track. They're designed to slide somewhat. Been there, done that.

This sort of seems like an accident waiting to happen to me, an SW-9 might not be an appropriate choice for an operation with steep grades like K&T. Those guys are lucky they weren't on board trying to get it running when it started to move.

"Moreover, an SW9’s handbrake only clamps down on a single brake shoe and isn’t meant to keep a locomotive stationary on steep grades."

So many questions:

Is this different from other units?

Why would unit have limited capacity handbrakes?

What constitutes a "steep grade"?

Why wouldn't there be some kind of warning about the limited use case brakes?

Assume for a minute this is a 2% grade. By a curious aspect of geometry that means the resulting force vector would be 2% unit weight, and guessing the unit weighs 100 tons that means the brakes can't handle a 4000 pound force. That seems pretty inadequate, especially since we know there are times some crews rely on the locomotive handbrake to hold a short cut of cars and the brakes need to hold in coupling/uncoupling.

I'm not familiar with the "Type A" trucks but that doesn't sound right to me. A single truck sounds more like it.

While I can't speak for other locomotive types, I can say it was true of the GP9 I used to work with - the handbrake clamped the shoes on only one wheel. On the other hand, the handbrake on GE 80-ton unit I spent time with clamped the brakes on one truck.

My explanation would be that this is related to how the brakes work on a given unit; on the GP9, the brakes for each wheel were operated by their own brake cylinder (thus 4 cylinders per truck), while on the 80 tonner, there was 1 cylinder per truck, on a freightcar, there is one brake cylinder that operates the brakes on both trucks. In each case, the handbrake works by mimicking the action of 1 brake cylinder, thus applying the handbrake sets whatever brakes would be applied by that cylinder and that cylinder only.

On the GP9, the handbrake chain was attached to the brake coming out of one cylinder on one side of one truck, thus cranking the hand brake applied the brakes on only one wheel, but effectively stopped one axle from rotating. On the 80-Tonner, the handbrake chain was attached to the rod coming out of the cylinder on one truck, so applying the handbrake would set the brakes on both axles of that truck. On a freight car, the one brake cylinder operates the brakes on both trucks, thus so does the handbrake.

I can attest that the GP9's single wheel handbrake was enough to hold it and the 4 cars coupled to it in place on a roughly 1/2% grade as well as make the whole train noticeably harder to move with the 80-Tonner. That said, I have no idea if it would have held the locomotive on a steeper grade, though I imagine it would have.

While it might appear that a handbrake operating on a single wheel of a locomotive would be inadequate, it is important to remember friction, or in this case adhesion to the rail, is the determining factor in a brakes effectiveness and that the weight carried by each wheel is the determining factor in how much friction or traction said wheel has. Given that the GP9 is putting over 60,000 pounds on each axle, while the 80-Tonner is putting only 20,000 pounds on each axle, the GP9's handbrake is actually offering more holding power. Even so, I would Hazzard a guess that if the rails were wet or frosty, one sliding axle might not do much to slow a locomotive down if it got moving on a steep and long grade and frost may well reduce the traction available to each wheel enough to render the hand brake a moot point, no matter how many wheels it was applying braking force to. (I can attest that frost on the rails made a very noticeable difference in the aforementioned GE 80-Tonner's braking ability and not in a good way)

Jason Midyette

If Preston Cook sees this thread he would probably be able to speak to the hand brake alternatives.

I lived next to the Rio Grande in the mountains (8,000 ft.) in Colorado for a year, and spent a lot of time up there for 10+ years, 2%+ grade for around 20 miles, and I don't recall ever seeing a single-unit light engine movement. They had light engine helper moves with two plus units a lot, but never a single unit. Work trains would be up there in the summer, with a single unit (usually an ex-NYC GP40 rebuilt at Burnham) but they never disconnected the engine from the train, where a mechanical issue on one unit could cause a problem with the brakes, and never a single-unit train in the winter.

The late Bernie O'Brien always used to caution his air brake students about the concentration of weight in the locomotive and how that demanded light moves be made with great care-even when the brakes were operating properly.

My guess is in that environment, they had the same considerations, and were no doubt guided by prior "adverse experiences" that failed to take that limitation into consideration.

BCO had a great caution about complacency, where he described taking a routine train out, only to find out it wasn't behaving as he expected "I got this little kick in the ass" and how he went around some curve above the limit to say "after I checked my shorts", I called NAME FORGOTTEN and he said "so you had your first experience with ABD brakes'.

He'll be gone a dozen years soon and I can't to begin to describe how his warning that any jackass can get a train going, the skill is stopping it safely has proved to be a useful admonition off the railroad.

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