Short hood
Encyclopedia
The short hood of a hood unit
-style diesel locomotive
is, as the name implies, the shorter of the two hood
s (narrower sections of the locomotive body in front and behind of the cab) on a locomotive. The short hood contains ancillary equipment, frequently a chemical-retention toilet
for crew use, and may contain a steam generator
for heating older-style passenger cars.
Normally, the short hood is the front of the locomotive, and may be referred to as the locomotive's "nose". Originally, this was not the case; railroads preferred to have the long hood leading, for additional crew protection in a collision. The requirement for increased visibility conflicted with this and ultimately gained precedence. Many locomotives originally had a short hood the full height of the locomotive (a high short hood). This gave extra equipment room and was often used to house a steam generator. Once the short hood was established as the front of the locomotive, manufacturers began to offer a low short hood (also referred to as the "standard cab" or "spartan cab" design), which was below the level of the locomotive's cab windows and allowed for center windows for better forward visibility. Many older locomotives were modified to have a low short hood and were referred to as chop-nosed.
More recently, it has become the standard for the locomotive's nose to be built full-width, instead of having a narrow short hood. This is officially known as a "safety cab" (sometimes "Canadian safety cab" since Canadian railroads were the first to specify these) and is often, but inaccurately, described as "wide cab" by railfan
s (the cab is no wider; it is the nose or short hood that is wider).
In Britain, almost all locomotives have two cabs, however some older English Electric
or British Railways designs have extended cabs with a strong resemblance to a "short hood" at both ends (usually referred to as the "nose" or "bucket"). Examples include the Class 37
, Class 40
, Class 45
and Class 55
. Some single cab designs did indeed have short and long bonnets (sic) on the American model, such as the Class 15
and Class 16
.
Hood unit
A hood unit, in railroad terminology, is a body style for diesel and electric locomotives. On a hood unit, the body of the locomotive is less than full-width for most of the locomotive's length, with walkways on the outside of the locomotive. In contrast, a cab unit has a full-width carbody for...
-style diesel locomotive
Diesel locomotive
A diesel locomotive is a type of railroad locomotive in which the prime mover is a diesel engine, a reciprocating engine operating on the Diesel cycle as invented by Dr. Rudolf Diesel...
is, as the name implies, the shorter of the two hood
Hood (vehicle)
The hood or bonnet is the hinged cover over the engine of motor vehicles that allows access to the engine compartment for maintenance and repair. In British terminology, hood refers to a fabric cover over the passenger compartment of the car...
s (narrower sections of the locomotive body in front and behind of the cab) on a locomotive. The short hood contains ancillary equipment, frequently a chemical-retention toilet
Toilet
A toilet is a sanitation fixture used primarily for the disposal of human excrement, often found in a small room referred to as a toilet/bathroom/lavatory...
for crew use, and may contain a steam generator
Steam generator (railroad)
Steam generator is the term used to describe a type of boiler used to produce steam for climate control and potable water heating in railroad passenger cars...
for heating older-style passenger cars.
Normally, the short hood is the front of the locomotive, and may be referred to as the locomotive's "nose". Originally, this was not the case; railroads preferred to have the long hood leading, for additional crew protection in a collision. The requirement for increased visibility conflicted with this and ultimately gained precedence. Many locomotives originally had a short hood the full height of the locomotive (a high short hood). This gave extra equipment room and was often used to house a steam generator. Once the short hood was established as the front of the locomotive, manufacturers began to offer a low short hood (also referred to as the "standard cab" or "spartan cab" design), which was below the level of the locomotive's cab windows and allowed for center windows for better forward visibility. Many older locomotives were modified to have a low short hood and were referred to as chop-nosed.
More recently, it has become the standard for the locomotive's nose to be built full-width, instead of having a narrow short hood. This is officially known as a "safety cab" (sometimes "Canadian safety cab" since Canadian railroads were the first to specify these) and is often, but inaccurately, described as "wide cab" by railfan
Railfan
A railfan or rail buff , railway enthusiast or railway buff , or trainspotter , is a person interested in a recreational capacity in rail transport...
s (the cab is no wider; it is the nose or short hood that is wider).
In Britain, almost all locomotives have two cabs, however some older English Electric
English Electric
English Electric was a British industrial manufacturer. Founded in 1918, it initially specialised in industrial electric motors and transformers...
or British Railways designs have extended cabs with a strong resemblance to a "short hood" at both ends (usually referred to as the "nose" or "bucket"). Examples include the Class 37
British Rail Class 37
The British Rail Class 37 is a diesel-electric locomotive. Also known as the English Electric Type 3, the Class was ordered as part of the British Rail modernisation plan....
, Class 40
British Rail Class 40
The British Rail Class 40 is a type of British railway diesel locomotive. Built by English Electric between 1958 and 1962, and eventually numbering 200, they were for a time the pride of the British Rail early diesel fleet...
, Class 45
British Rail Class 45
The British Rail Class 45 also known as the Sulzer Type 4 diesel locomotives were built by British Rail at their Derby and Crewe Works between 1960 and 1962...
and Class 55
British Rail Class 55
The British Rail Class 55 is a class of diesel locomotive built in 1961 and 1962 by English Electric. They were designed for the high-speed express passenger services on the East Coast Main Line between and Edinburgh. They gained the name "Deltic" from the prototype locomotive, DP1 Deltic, which...
. Some single cab designs did indeed have short and long bonnets (sic) on the American model, such as the Class 15
British Rail Class 15
The British Rail Class 15 diesel locomotives, also known as the BTH Type 1, were designed by British Thomson-Houston, and built by the Yorkshire Engine Company and the Clayton Equipment Company, between 1957 and 1961.- Design history :...
and Class 16
British Rail Class 16
The North British Type 1 was a type of diesel locomotive ordered under British Railways' 1955 Modernisation Plan. Like other Type 1 designs, they were relatively small locomotives intended primarily for local freight traffic....
.