Engineering Plant

The SHIELDS’ engineering plant had four boilers to make steam. That steam was used to turn her two propellers driving her through the water at speed up to 37 knots (almost 43 mph). Steam was also used to power pumps and other auxiliary machinery as well as to make electricity and to convert sea water into fresh water for cooking, drinking and showering. The engineering plant was housed in four big compartments and a few smaller ones.

Four Big Compartments

The four big compartments were the biggest on board. Each extended the entire way from port to starboard and from keel to main deck. Going aft on the main deck the first big compartment was the forward fire room; then the forward engine room, then the after fire room, then the after engine room. Each compartment had two hatches through the main deck, one on the port side, one on the starboard side. There were no doors in the bulkheads separating any of these big compartments from one another or from the rest of the ship. To go from compartment to compartment a sailor had to climb the ladder to a hatch and the travel on the main deck. Since the main deck was exposed to the weather, a sailor could sometimes get wet going from compartment to compartment or simply going on or off watch.

The forward fire room was almost completely filled with two boilers lined up fore and aft. The first boiler turned water into steam by burning fuel oil injected into it by one or more of its seven injectors. This steam at 650 pounds per square inch (psi) and 850ºF was sent to an engine room to drive SHIELDS through the water and to do many other things. The second boiler did the same thing. During normal cruising only one boiler was “on the line” i.e. making steam; at general quarters, both were.

Just aft of the forward fire room was the forward engine room housing a high pressure turbine and a low pressure turbine. While underway steam produced in a fire room was fed to the high pressure turbine making the turbine spin at high speed. This steam left the high pressure turbine at atmospheric pressure i.e. no pressure at all. But there was still energy to be recovered and that energy was recovered by turning the steam back into water. This was done in an enormous condenser the size of a pick-up truck. The condenser created a vacuum. This enabled SHIELDS to take steam from the high pressure turbine at atmospheric pressure, send it to the low pressure turbine and have the low pressure turbine wring out the last bit of energy by exhausting this steam to a vacuum.

Both the high and low pressure turbines spun too fast to directly turn the propellers. Their speed was reduced such that the propeller(s) turned at a much slower speed. This was done by a reduction gear connected to the starboard shaft.

Also in the forward engine room was an electrical generator powered by its own steam turbine and a large number of special purpose pumps. We had pumps to pump salt water through the condenser; to pump fresh water from the condenser back to the boiler(s); to pump lubricating oil into a centrifugal cleaner to keep it pristine; and pumps to keep salt water pressure on the fire mains to be used for fire-fighting. This salt water in the fire mains was also used to flush the toilets and urinals which flushed 24 hours per day seven days per week. We had an ocean full of salt water and it was important to keep the heads sanitary. It would have been wasteful to use fresh water for this purpose.

The forward engine room was also called “main control”, short for “main engine control” and was my general quarters battle station.

The after fire room was almost identical to the forward fire room with one minor exception; the starboard shaft from the forward engine room ran through it. The shaft was about a foot in diameter and was normally painted navy grey. One day I entered the after fire room and found that the crew had painted it with red and white stripes just like an old-time barber pole. I got dizzy watching it go around. It certainly did not conform to Navy Regulations, but “what the hell” I thought, “it still performs its intended function and if it makes the crew happy, why should I object”. I said nothing. I doubted that the captain or the exec would ever see it since they rarely entered the engineering compartments.

The after engine room was almost identical to the forward engine room except that it drove the port shaft. There were actually two engine order telegraphs, one connected to the after engine room for control of the port shaft, one in the forward engine room to control the starboard shaft. In the manner the conning officer on the bridge could tell us whether he wanted each engine to go forward or reverse and how fast. For example he ring up “ahead one-third” on the starboard shaft and “back on-third” on the port shaft causing SHIELDS to twist, a handy feature when approaching or leaving a pier.

Some Smaller Compartments

The after-most compartment on the ship was the steering gear room dedicated to the hydraulic equipment that moved the rudder.

SHIELDS had a fully equipped machine ship with a lathe, a drill press and lots of other shop equipment such that we could repair almost anything.

Just outside my stateroom in officers country was a compartment housing the emergency electrical generator. It was driven by a diesel engine and was set to start automatically if we “lost the load” navy-speak for a loss of electrical power. This emergency generator was not powerful enough to provide all SHIELDS needs but was sufficient to supply essential services.

The smallest engineering compartment was the size of a clothes closet and was located on the main deck amidships. Stored in that closet were: fire-fighting equipment; oxygen breathing apparatus (OBA) for use in smoky areas; timbers for shoring; material for patching holes in the hull; electrical cables; portable pumps for removing water from flooded compartments; and other damage control equipment.