Wednesday, March 4, 2009

Blind Drivers and Slip Coaches?

Port Townsend, today. A fellow by the name of John Wooden once said, “It’s what you learn after you know it all that counts!” And that is never so true as it is about the railroading hobby. Keep an open mind and you can learn something new on a regular basis!

What in the heck are "blind drivers" and "slip coaches?"

Well, a few months ago I did a piece about the CNR 2514, wherein I mentioned I had seen a Santa Fe Type – 2-10-2 - CNR 4304 - in town. The joke being one of sending her out to Prince Rupert to straighten curves. In regards to that article, a fellow sent me an email asking if that series of locomotives had “blind drivers.” At first I thought I was being baited into a joke.

But as I have come to learn, the purpose of “blind drivers” or flangeless wheels sets, is to reduce stresses on track curvature, and is found on some long wheelbase steam locomotives. Since the weight of the engine keeps the wheels on the tracks, the flange can be eliminated on certain wheel sets without affecting adhesion.

The practice of “blind drivers" seems to be common on narrow gauge locomotives, as discussed in great detail here. I’m not sure how prevalent the practice was on bigger locomotives; perhaps you can share this by clicking on the “Comment” below.

As to the subject of “slip coaches;” apparently it was not uncommon in Great Britain. In fact the technique was used for more than 100 years, dating back to 1858. The technique must have been quite safe to be used for so many years. The last “slip coach” operation was performed in 1960!

Simply put, passenger coaches were uncoupled from moving passenger trains churning along at 50 to 60 miles per hour. Hopefully the passenger car would be stopped within the bounds of the station where upon passengers would disembark, allowing the main consist to press on with its tight schedule!

Working a slip was quite a skilled job. The slip guard (trainman) had only the mechanical hand brake with which to stop. There were special precautions against the possibility of collision after slipping from the main train. If at any time the trainman felt the maneuver maybe dangerous, he had but to flag the engineer to stop.

A switch engine stood by to correct “over or under slipping” or to pick up cars slipped on middle tracks of three or more passages. And it was incumbent upon passengers to know exactly what car they were in before they got “slipped!”

I found a detailed narrative of the “slip coach” technique. In fact, an entire book was written on the subject, which must be interesting reading.

Slip coaches were used on the Great Western, LM&S, L&NE, Furness, and even in France.

3 Comments - Click here:

LinesWest said...

Good stuff as usual! I had to chuckle at: "The joke being one of sending her out to Prince Rupert to straighten curves. "

It made me recall a story my dad told of his time with the ATSF in Kansas. He was a brakeman on one of the branch lines that wandered out from Dodge City and headed east to the Colorado line. The grain rush of late summer usually required some extra power and one year the ATSF supplied one of their really large 2900 class 4-8-4s. The crew wasn't exactly sure what they were supposed to do with this beast, especially when they found it was too big to be turned at the end of the run. So it ran backwards all the way back to Dodge City. I assume with an impressive set of 40' grain service boxcars in tow.

As an avid model railroader, I had run across blind drivers before, but I always assumed they were just on the models ... until now. Thanks - Leland

Robert in Port Townsend said...

Pretty hard to stump those old timers - I'm sure it took less than a minute to decide to do a reverse move - no biggie! Followed by a blistering wire to Division!

As it turned out with the 2-10-2 in Prince Rupert, the "wye" was biggest worry, because of its tight radius. Had she dropped on the ground - well...

The road foreman personally supervised her end-for-end. The report was that there was screeching from both the foreman and the rails!

I have some slides of her somewhere in this pile I am working through.

Unknown said...

Slip Coaching seems dangerous! I'm sure it's safer than it sounds. It would probably require a ton of experience, which lends credibility to your recent comments about the texting engineer back East. No matter the technology, nothing beats time in the seat.

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