B Units

A B unit, in railroad terminology, is a locomotive unit (generally a diesel locomotive) which does not have a driving cab or crew compartment, and must therefore be controlled from another, coupled locomotive with a driving cab (an A unit).
The terms booster unit and cabless are also used. The concept is largely confined to North America. Elsewhere, locomotives without driving cabs are rare.
The reasons railroads ordered B units included the fact that a B unit was slightly cheaper. With no driving cab, B units lack windshields, crew seats, radios, heating, and air conditioning.
==Gallery==
CSX F7B 119-bc.jpg
CSX F7B 117-s.jpg
CSX F7B 117-bc.jpg
CSX0119-bc.jpg
CSX0117sbd.jpg
CSX0117-s.jpg
CSX0117-bc.jpg
Picture 792.jpg
Fb8128.jpg
ALCOC855B.jpg|The B unit of the Alco Century 855.
MILWx1.jpg
Category:American locomotives
Category:Diesel locomotives
Category:Four-axled diesel locomotives
Category:Santa Fe locomotives
Category:CSX locomotives
Category:Locomotives
Category:Locomotive Parts
Category:Diesel Locomotive Principles
Category:B-units