Tunnel Motor Question

Railroadforums.com is a free online Railroad Discussion Forum and Railroad Photo Gallery for railroaders, railfans, model railroaders and anyone else who is interested in railroads. We cover a wide variety of topics, including freight trains, passenger and commuter railroads, rail news and information, tourist railroads, railway museums and railroad history.

brad_in_omaha

Active Member
Probably a stupid question, but why do they not make tunnel motors anymore? There are still tunnels all over the country...
 

kenw

5th Generation Texian
because part of the theory behind them (the lowered intakes) didn't prove as big a benefit as originally thought, and what did work about them (much larger radiator intakes) was incorporated into newer designs. You will notice that most newer engines have much, much larger radiators, this has the same (and even more) cooling effect as moving more air over smaller radiators.
 

Pat

Photo Critiques Welcome
I've read there was a difference in radiator life. The fans blowing through the radiator like a tunnel motor gave particulate a higher velocity at the blade tips than fans that pulled through radiators. The article said tunnel motors had a shorter radiator life as a result.
 

kenw

5th Generation Texian
I've read there was a difference in radiator life. The fans blowing through the radiator like a tunnel motor gave particulate a higher velocity at the blade tips than fans that pulled through radiators. The article said tunnel motors had a shorter radiator life as a result.
Generally speaking, and with lots of caveats, pull thru gives a better distribution of air over the coils than push thru. Lots of things impact that, like inlet/outlet geometries, air paths, coil-blower spacing, etc, but all being equal pull thru is more efficient.
 




RailroadForums.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com

RailroadBookstore.com - An online railroad bookstore featuring a curated selection of new and used railroad books. Railroad pictorials, railroad history, steam locomotives, passenger trains, modern railroading. Hundreds of titles available, most at discount prices! We also have a video and children's book section.

ModelRailroadBookstore.com - An online model railroad bookstore featuring a curated selection of new and used books. Layout design, track plans, scenery and structure building, wiring, DCC, Tinplate, Toy Trains, Price Guides and more.

Affiliate Disclosure: We may receive a commision from some of the links and ads shown on this website (Learn More Here)

Top