Re: Slippery locomotives

There could be several causes for the slippery behavior shown in the video. The initial section of line appears to be overgrown with grass. Grass crushed by the drivers makes for slippery rails.

The most likely cause is a low factor of adhesion. As designed, these engines produced 800 horsepower. Many were modified by Porta which greatly increased their power. The second batch, of which 119 is one, were built incorporating Porta's modifications and the locos were now rated at 1,200 horsepower. This is good when running at speed, but makes for a very slippery loco when starting and at low speeds.

The South African class 26, "Red Devil", which incorporated a number of Porta and Wardale modifications, was also very slippery when starting a train. It developed 4490 horsepower at around 45 mph, a 43% increase over the output of a class 25. Since the class 26 was a modified class 25 with no increase in weight on drivers, it was a very slippery locomotive until reaching a speed where the full horsepower could be utilized.

Michael Allen



Edited 2 time(s). Last edit at 02/10/2019 10:50AM by trainrider47.