by Allen Hazen
It seems to be generally agreed that the BL-2 was a flop: discontinued after 59 units, replaced in the EMD catalogue by the very successful but radically different GP-7.
The basic package SHOULD have been successful: use the works of the popular F-3(*) in a roadswitcher configuration. The BL-2's body design, however, seems to have been a disaster: cramped engine room annoyed maintenance people and (more importantly) it was apparently expensive to build.
So, why was it chosen in the first place? EMD had long experience with switchers, had built elongated switchers (= "light roadswitchers"), had even (in transfer units for the IC) put its 16-cylinder engine in a switcher-style carbody. And the competition (Alco AND Baldwin) had shown the way, marketing roadswitchers of standard design (= frame like an elongated switcher frame, non-structural hood over the machinery). So why did EMD try to use a semi-streamlined truss carbody? Was there any rationale for it?
Thought. Truss-style bodies can be made lighter than standard road switchers. The BL-2 was, in fact, somewhat lighter than a GP-7, I think: an internet source, "Thedieselshop.us," has a description of the BL-2 that says it weighed 230,000 pounds. Their page on the GP-7 says 246,000 (another source-- a Simmons-Boardman booklet that probably draws on contemporary Car and Locomotive Cyclopedias) says the GP-7 was 240,000 pounds.
"BL" supposedly stands for "Branch Line." Is it possible that EMD chose the BL-2's carbody in the hope that they could minimize the weight of the unit, and so sell it to railroads with light-rail, light bridge, lines?
(*) According to Thedieselshop.us, the BL-2 had the newer, D-27, traction motors. So -- if you distinguish between the F-3 and the F-5 -- the BL-2 seems to have been a roadswitcher F-5. Which makes sense given its production dates.
The basic package SHOULD have been successful: use the works of the popular F-3(*) in a roadswitcher configuration. The BL-2's body design, however, seems to have been a disaster: cramped engine room annoyed maintenance people and (more importantly) it was apparently expensive to build.
So, why was it chosen in the first place? EMD had long experience with switchers, had built elongated switchers (= "light roadswitchers"), had even (in transfer units for the IC) put its 16-cylinder engine in a switcher-style carbody. And the competition (Alco AND Baldwin) had shown the way, marketing roadswitchers of standard design (= frame like an elongated switcher frame, non-structural hood over the machinery). So why did EMD try to use a semi-streamlined truss carbody? Was there any rationale for it?
Thought. Truss-style bodies can be made lighter than standard road switchers. The BL-2 was, in fact, somewhat lighter than a GP-7, I think: an internet source, "Thedieselshop.us," has a description of the BL-2 that says it weighed 230,000 pounds. Their page on the GP-7 says 246,000 (another source-- a Simmons-Boardman booklet that probably draws on contemporary Car and Locomotive Cyclopedias) says the GP-7 was 240,000 pounds.
"BL" supposedly stands for "Branch Line." Is it possible that EMD chose the BL-2's carbody in the hope that they could minimize the weight of the unit, and so sell it to railroads with light-rail, light bridge, lines?
(*) According to Thedieselshop.us, the BL-2 had the newer, D-27, traction motors. So -- if you distinguish between the F-3 and the F-5 -- the BL-2 seems to have been a roadswitcher F-5. Which makes sense given its production dates.