As the title says…
Also, when were they and did some RR use them while others didn’t?
Please?
TIA [8D]
A Horst of a different color! The main time I’ve seen them was on rebuilt GP’s, don’t know the reason why. Often these are referred to as “Paducah Geeps” after the name of the railway shop where they were rebuilt (Santa Fe?). I made a GP-10 model of a Precision Leasing diesel some time ago, and added the Detail Associates Horst air filter, as well as four separate exhaust ducts on the roof.
Maybe someone else can fill you in on the reasons.
I’m not familiar with this particular type of air filter, but if they were from the Paducah shops they were on Illinois Central locomotives because the IC owned the Paducah shops.
A Google search for Horst air filters took me to sites in Germany.
The other two posters are correct. These showed up on the Illinois Central “Paducah Rebuilds”. Basically, the IC started a major rebuilding program, I believe in the early 70’s, of their first generation EMDs, GP7s and GP9s and various SDs. The rebuilt units were called GP8s (from GP7s) and GP10s (from GP9s). Some of these units found their way onto shortlines and other RRs since they were cheaper than new locos and the improvements made by IC helped with fuel mileage and reliability. Here are a couple of links to pictures of various 8 and 10s. If you google Paducah Rebuilds, you’ll get plenty more. The distinguishing feature is the air filter housing on top of the loco, I believe the Horst was easier to maintain than the original EMD air filters and improved performance.
Rick
The advantage to the Horst air filters is that they are a central air intake system. The early geeps (GP-9’s are a great example) draw their intake air in through all those grilles in the carbody doors which have air filters behind them. In truth, they tend to suck unfiltered air in through every crack and crevice in the carbody. Worse, if the carbody filters get clogged, the only way for the engine to get air is through those cracks and crevices. Not good and very dirty.
It’s a popular re-fit for early geeps for exactly this reason. Later locomotives by EMD had central air intakes, so there was no need for the Horst air filters when rebuilding them.