Barrack Block B, Royal Artillery Barracks (also known as Le Cateau Barracks)

This is a former Royal Artillery barracks, built between 1874 and 1875. It was designed by Lieutenant General Charles Brisbane Ewart RE, who was Deputy Director of Works for Barracks at the War Office. It is part of the Royal Artillery Barracks, also known as Le Cateau Barracks, in Colchester. Previously listed as Cavalry Barracks B, Le Cateau Barracks, Colchester Garrison, this building represents the last remaining example of the new cavalry barracks layout developed at Aldershot in the 1850s.

The building is constructed of red brick with yellow brick bands and stone lintels, topped with a slate roof and brick ridge stacks. The design is rectangular and single-depth, incorporating corner officers' stables and stores. The exterior has a two-storey, 6:4:6-window range, with similar front and rear elevations. It features coped end gables and patterned brick eaves, as well as projecting two-window single-storey blocks at each end and a central pediment gable. Square stable windows run along the north side, with a central segmental-arched double door, left-hand doors and a right-hand window at the end blocks, and a louvred oculus. The upper floor is set back to form a balcony between the gable and end blocks, featuring diagonal iron railings. The south side has a band of patterned brick below the stable windows and three doorways separated by windows on the central gable. The upper floor windows have 4/4-pane sashes.

The stables internally are divided into two sections by central cast-iron posts, which support a brick jack-arch floor with ties between the joists. There are office and storerooms at each end. A central imperial stair leads to the 22-man barrack rooms on each side of the NCO's room.

This barracks was a fireproof building with enhanced ventilation designed for the soldiers, representing an advanced design for cavalry barracks while retaining a traditional layout of men's rooms above stables. It was the second permanent barracks built at Colchester, following the adjoining Calvary Barracks constructed between 1862 and 1864. It forms part of a group of related buildings.