After yesterday's post about steam engines on South African railroads, I received a couple of questions about it. The first was about Garratt-type locomotives, which were never used on US railroads and thus sparked the curiosity of several knowledgeable readers. The second was about the Montagu Pass, which I described as 'magnificent'.
Garratt locomotives were a unique design, of particular value on narrow-gauge railroads that couldn't support the weight of very large or powerful engines. They were articulated, with a steam engine at either end fed by a set of boilers in a central unit. This meant that a single Garratt engine could generate 60% to 80% more power than a conventional locomotive. The central boiler unit also meant that it was more economical in its use of coal and water than two locomotives would have been, and required only one crew to operate it instead of two. The weight on the rails was also more evenly spread, as a single Garratt engine would put less pressure on rails, bridges and ballast than two conventional units. Finally, its articulated design meant that it could handle tight curves and restricted conditions much better than fixed units. You can read a good summary of the Garratt's advantages and disadvantages here.
They were an ingenious solution to a set of conditions often encountered on colonial railroads. More than 1,600 were built, in a large range of different models and sizes, and a large number have survived in museums. At least two are still in use on South African railroads, in private hands as far as I know.
The Garratts were often used on the Montagu Pass, because it's very narrow in parts, very twisty, and extremely steep, so the higher power output of the double-engine design was very useful there. Here are two video clips illustrating the pass and the Garratts that worked there. I recommend watching both in full-screen mode.
The first shows the departure from George and the ascent of the Pass. I remember this trip so well that it made me almost painfully homesick to watch this clip this morning. I don't want to go back to South Africa - there are too many very bad memories for that - but this made me smell the fynbos vegetation again, and the coal smoke from the engine.
The road you can see across the valley from the railway line is the Outeniqua Pass, built using Italian prisoner-of-war labor during and after World War II to replace the much narrower and steeper Montagu Pass, which was originally designed for ox-wagons and horse travel, and thus less suitable for motor vehicles. It was extensively modernized during the 1990's. Again, I've traveled that road many, many times.
The second video clip shows the Union Express - once a mainline train, but now an occasional tourist event - leaving Oudtshoorn, in the Little Karoo, and heading towards the Montagu Pass and George from the inland plateau. It shows the Garratt engines to good advantage, as well as the beauty of the route - one of the loveliest I've ever traveled by rail or road.
Yes . . . I may never want to go back, but I can still feel homesick . . .