The short hood on an American locomotive is commonly known as the front of the locomotive. Typically used to house electrical and mechanical instruments as well as a chemical toilet, the low short hood offers added visibility for the engineer and crew as compared to the taller version known as the high hood. The earlier versions of the short hood were narrower than the full width of the locomotive using walkways and ladders along the side for easy exit and entry. Later versions use a full-width hood running the entire width of the locomotive. This design is referred to as a safety cab due to the added protection it offers the train's crew in the event of a collision.
In the earlier locomotives, the long end of the locomotive was used as the front of the train. This was done primarily to protect the crew in the case of a collision. It was later determined that the better vision permitted by using the short hood as the front of the train was safer.
Many railroads converted their inventory of high short hood locomotives to the lower hood design to allow for better vision. The Canadian railroads were the first to use the short, wide hood as the front of the locomotive, which is why the short cab width hood is often called the Canadian safety hood. This design is commonly, albeit mistakenly, called a wide cab locomotive by railroad fans since the cab is no wider than the nose or hood.
Frequently, railroad crews can be stranded on the tracks for long periods of time. In cases like these, having a chemical toilet in the short hood is a welcome addition to the train. Some locomotives also have small coolers mounted inside the short hood in which bottled water is kept for the crew. This was occasionally kept in the caboose, however, the elimination of the caboose has required train crews to adapt and carry more of their necessities in the short hood of the locomotive.
Collisions are a reality in railroading. Crews are often put in a dangerous spot when the vehicle a train collides with is a tanker truck or another type of vehicle that might burst into flames or explode on contact. Even lumber, pipe or bricks can become airborne when struck and make their way into the locomotive's cab, injuring or even killing a member of the train's crew. The safety cab helps to protect the crew members by placing more protective steel between the crew and the collision.