The aft engine room contains the two main propulsion diesel engines on the starboard side, the ship's service generator on the port side, the aft electrical distribution panel and ancillary pumps and compressors needed to support the main propulsion equipment. The propulsion plant of the Evarts and Cannon class destroyer escorts essentially duplicated the propulsion machinery found in WWII US submarines. The primary difference being that there were no batteries.

As initially conceived, all destroyer escorts were to have steam turbine machinery similar to destroyers. However, a limitation in the ability to produce reduction gears in the needed quantities caused other sources of propulsion to be sought. Thus, many destroyer escorts, such as the SLATER, were built with diesel propulsion. While the diesel machinery did not produce the high horse power and speed of the steam machinery, it did provide for longer range and economical operation.

The specific equipment found on the upper level includes the #2 Ship's Service Switchboard for running the other electrical equipment and lighting aboard the SLATER, Lubricating Oil Tanks with Lube Oil Transfer Pump (Pump, Lube Oil Transfer, Rotary Type, Blackmer Pump Co., 25 GPM, 50 PSI, 860 RPM, Motor data: General Electric Co., 2 HP, 865 RPM, 440 VAC), Air Compressor, originally used to charge the air flasks on the torpedo tubes and a Motor Generator Set (Motor-Generator Set, Allis-Chalmers Co. Generator Data: 2 each 8 1/2 KW, 120 VDC; I each 2 KW, 120 VDC. Motor Data: 30 HP, 440 VAC, 1740 RPM).

The specific equipment on the lower level includes the two GM diesel engines (numbers three and four) for main propulsion, located on the starboard side. These are 16 cylinder Model 278s, and each drove a separate direct current generator located in the next compartment aft, B-4. (Engine, Diesel, Main Propulsion, General Motors Co., Model 16-278A, 1700 HP, 750 RPM, 16 cylinder, 2 cycle.) This propulsion equipment is a duplicate of space B-1. The duplication of machinery was a standard feature of US World War II Destroyer design, and it enabled our ships to withstand incredible battle damage and still survive. Also in this room is the #3 diesel powered Ship's Service Electrical Generator. (Generator, Ships Service, Westinghouse Electric Co., SN 124619P525, 200 KW, 250 KVA, 321 Amps, 450 VAC, 60 Cycle, 3 Phase. Diesel Data: General Motors Corp., Cleveland Diesel Engine Division, Model 8-268A, 8 Cylinder, 2 Cycle, 350 HP, 1200 RPM.) Also located here are 2 lube oil service pumps (Pump, Lube Oil Service, Gear Type. Motor Data: Howell Electric Co., 3/4 HP, 1160 RPM, 440 VAC), 2 salt water circulating pumps (Pump, Salt Water Circulating, DeLaval Co., Centrifugal. Motor Data: Allis-Chalmers Co., 7 1/2 HP, 1740 RPM, 440 VAC.), and a fire and bilge pump (Pump, Fire & Flushing/Fire & Bilge, Ingersoll-Rand Co., Centrifugal, 200 GPM, 100 PSI, 3500 RPM. Motor Data: General Electric Co., 20 HP, 3500 RPM, 440 VAC). Pump Diesel Oil Transfer, Pump Diesel Oil Service, 2 Sharples Purifier lube oil/fuel oil.