A caboose is a manned North American railroad car coupled at the end of a freight train. Cabooses provide shelter for crew at the end of a train, who were formerly required in switching and shunting, keeping a lookout for load shifting, damage to equipment and cargo, and overheating axles. A similar railroad car, the brake van, was used on British and Commonwealth railways (the role has since been replaced by the crew car in Australia). On trains not fitted with continuous brakes, brake vans provided a supplementary braking system, and they helped keep chain couplings taut.