By Captain George Stewart, USN (Retired)
This article is intended to provide a basic description of the ex USS Charleston (PG 51) when it served as the USTS Charleston, the training ship for the Massachusetts Maritime Academy during the period between 1948 and 1957.
USS Charleston (PG 51) was one of only two Erie Class Patrol gunboats originally built for US Naval service during the 1930s. Its’ keel was laid down at the Charleston Naval Shipyard, Charleston, South Carolina on 27 October 1934. It was launched on 25 February 1936 and commissioned on 8 July 1936. Pertinent characteristics of the ship were as follows:
- Length – 328’6”
- Beam – 41’3”
- Design Draft – 12’9”
- Design Displacement – 2000 tons
- Full Load Displacement – 2339 tons
- Speed – 19.6 knots
- Accommodations (Original) 231 including Admiral & Staff
- Armament (World War II) – Four 6”/47 semi enclosed gun mounts, Four quad 1.1” antiaircraft mounts, Six 20 mm gun mounts, and two depth charge racks
- Propulsion – Geared steam turbines driving twin screws, 6200 SHP
- Boilers – Two three drum “A” express type, 300 psi
- Range – 12,000 nautical miles at 12 knots
As originally configured the ships could also carry one floatplane amidships. The ship was not large enough to hold a catapult, therefore the aircraft had to be lowered into the water and raised back on board by means of a crane.
These ships were actually designed like small cruisers. They were built specifically to protect American lives and property in places around the world. They were never intended for major fleet actions and they conducted most of their operations alone.
The Erie class gunboats were not particularly successful. Only two ships of the class were built. However at the same time, the US Coast Guard decided to adopt the same basic hull and machinery design, with some variations for their 327’ “Treasury Class” cutters in order to minimize costs. These ships were originally commissioned as patrol gunboats (WPG) but their designation was changed to high endurance cutters (WHEC) in the 1960s. The first of these ships, the USCG Campbell (WHEC 32) was commissioned on 16 June 1936 and eventually seven ships of this class entered service during the 1936-1937 time frame. The USCG Bibb (WHEC 31) was actually built alongside Charleston at the Charleston Naval Shipyard and it entered service only a few months later. Unlike the gunboats, these cutters were extremely successful with five of the seven remaining in active Coast Guard service up until the mid 1980s. It is understood that originally it was planned to transfer Charleston to the Coast Guard at the end of World War II. However this transfer never took place, most probably because of the costs associated with the conversion due to the necessity to change out the major weapons systems. The USCG Taney (WHEC 37) remains on display in Baltimore, Maryland as a museum ship.
After commissioning and shakedown, Charleston departed Norfolk, Virginia in February 1937 and joined a task force in the Mediterranean that was established to protect American interests during the Spanish Civil War. After returning to the United States and undergoing an overhaul the ship sailed for Balboa in the Panama Canal Zone where it picked up an assignment as the flagship for the Special Services Squadron in the Caribbean. Between 1938 and 1940 the ship conducted exercises off the East Coast and visited various ports in Mexico and Central America.
On 8 September, 1940 the ship left the East Coast and was sent to Seattle, Washington where it began a new assignment as the flagship for the Commander of the Alaskan Sector of the Thirteenth Naval District. Between 1940 and 1941 it made a number of cruises to Alaska and the Aleutian Islands. After the United States entered World War II it was assigned to patrol and escort duties in the Alaska /Aleutian Islands areas. The ship was based at either Dutch Harbor or Kodiak during the balance of the war. In 1943 the ship supported the invasion of the island of Attu which had been taken over by the Japanese. During that period it conducted shore bombardment, screened and protected escorts, and provided convoy escort services. During one Japanese air attack, the ship was required to avoid several torpedoes and it shot down one of the attacking aircraft. While assigned to the Aleutians the ship completed 130 escort missions involving a total of 253 convoyed ships.
At the end of the war the ship was initially assigned duties in the Far East with stops in Hong Kong and Shanghai before returning to the United States in March 1946. It was decommissioned in San Francisco in May 1946 and turned over to the Massachusetts Maritime Academy in 1948 for use as a training ship based at Buzzards Bay. It served in that capacity until 1957 when it was sold to an Italian investor for use as a floating night club and hotel. Its’ final fate is unknown.
Charleston’s only sister ship’ USS Erie (PG 50) was built at the New York Navy Yard in Brooklyn, New York and it was commissioned at about the same time as Charleston. During the war it was based in the Caribbean where it was beached in November 1942 after being torpedoed by a German U-Boat. It was then towed to Willenstadt, Curacao where it capsized and sank on 5 December 1942. In 1943 it was struck from the naval register.
The following photo shows Charleston in its wartime configuration.
A number of changes had to be made in order to make the ship suitable for duty as a school ship. All of the ship’s wartime armament had been removed with the exception of one of the after 6” mounts. The removal of all of this topside weight resulted in an increased metacentric height which, if anything, made the ship too stable. Naval architects refer to this as being “stiff.” During the first few days of the annual training cruises the ship often encountered a seaway off Cape Hatteras and it would start violently rolling. The majority of the cadets and some of the instructors would become seasick. This condition would last until calmer waters were reached in the Caribbean. When it was originally commissioned, Charleston was fitted with portholes along the side. These had been sealed up in its wartime configuration but they had been reinstalled to provide at least some degree of ventilation as the ship had no air conditioning system. Invariably some would be found to be leaking under the conditions described above resulting in water with a very unpleasant odor sloshing around in the berthing compartments.
Although their propulsion powering requirements were far lower than those of a destroyer, Charleston and Erie’s machinery plants incorporated numerous advancements in marine engineering that had been first introduced aboard the Farragut Class destroyers which were designed in 1932 and entered service in 1934 and 1935. These advancements included the use of superheated steam at higher pressures, air encased boilers, semi enclosed feed water systems, an AC electrical distribution system, an emergency diesel generator, and a number of other improvements. The ship had a single rudder operated by an electro-hydraulic steering engine. Prior to 1930, steam steering gears had been standard aboard naval vessels. Although Charleston was not a destroyer, a number of these design features carried over to the design of surface combatant ships that were built up through and during World War II. During the 1920s, little progress had been made in this area due to an excess of “four pipe” destroyers left over from World War I and limitations imposed by the Washington Naval Treaty of 1922, along with the London Naval Treaty of 1930.
Following is a description of the Charleston’s main machinery plant as it was configured during its’ time as a training ship. The machinery was located in three compartments. From fore to aft these were.
- Boiler Room – B1 -Ship’s boilers and associated support systems and equipment.
- Engine Room – C1 – Both main engines mounted side by side and other major steam cycle components and support equipment.
- Auxiliary Room – C2 – Ship service turbo generators, main switchboard, distilling plant, and other auxiliary machinery. The port and starboard shaft alleys were located immediately aft of this space.
Direct access was provided between all of these spaces by means of watertight doors through the transverse bulkheads. By the time World War II came around, direct access between machinery spaces was no longer permitted in new ship designs and it was “up and over” to go from one space below the Main Deck to another.
Charleston had a pair of water tube express type boilers manufactured by Babcock & Wilcox. The boilers were located side by side with the firing aisle facing forward. The boilers were of the “A” Type with a single steam drum and a pair of water/mud drums, one on either side with tube banks. This type of construction later fell out of favor because of the requirement for multiple uptakes. Each of Charleston’s boilers actually had four uptake connections, two on either side of the steam drum. Unlike most boilers of later design, these boilers were not fitted with heat recovery devices such as economizers or combustion air pre heaters. One of the major reasons for going to a single uptake was the fact that it made it much easier to include these features in the design. The boilers were fitted with integral superheaters. Auxiliary steam was supplied by desuperheaters located in the steam drum. The design operating pressure of the boilers was 330 psig. Superheated steam was supplied to the main turbines and turbo generators at a pressure of 300 psi and a temperature of 522° F.
A view of the port boiler burner front is shown in the following illustration. The ship burned an intermediate grade of fuel, similar to the Navy Special Fuel Oil (NSFO) that was in use at that time.
Charleston was built before the days of automatic combustion control, burner management systems, wide range steam assisted atomizers, three element feed water regulators, and other automatic boiler control devices. All burner front operations were accomplished manually. This practice continued on all combatant ships that served during World War II and the Navy did not start incorporating automatic combustion and feed water controls into their ships until the late 1950s and early 1960s. The configuration of the burner fronts and operating procedures aboard Charleston were very similar to those found aboard the Fletcher, Sumner, and Gearing Class destroyers built during the war.
At the time, USTS Charleston was berthed at the finger pier at Buzzards Bay on the Cape Cod Canal in approximately the same location as the school ship is today and there was no shore steam supply available. This made it necessary to utilize one of the main boilers for heating and hot water supply. The practice was to keep the auxiliary steam stop open and periodically “boost” the boiler by lighting and securing one burner as required to maintain steam pressure between approximately 150 and 300 psi. During these operations the Boiler Room was manned by two cadets. This provided absolutely great training at one time or another for all engineering cadets and this training would prove to be very useful during future naval and commercial assignments.
When the ship was underway the scenario in the Boiler Room was entirely different. Depending on whether one or two boilers were on the line, as many as 8 cadets could be found on watch. During our Second Class cruise we encountered some heavy weather off Cape Hatteras causing many of the crew members, including both cadets and instructors to become violently sea sick. I decided to make a midnight tour of the Boiler Room where I found only one lower classman fully functional with all of the other watch standers passed out on the deck plates. He was happily firing the single on line boiler while smoking a cigar despite the fact that this was one of his first days at sea and he had never seen the boilers fired continuously before. But we all survived.
Charleston had a single Engine Room (C1). The most prominent features were the two main engines located side by side in the middle of the space. There were two operating levels. Engine control was accomplished from a single main throttle board on the operating platform which ran across the forward part of the space on the upper level. The lower level was devoted to main engine and steam cycle support equipment including the main condensers, associated pumps, and main engine lube oil system components.
An illustration of the main throttle board follows. It was well laid out with all pertinent gauges in easy view of the operators. Each of the two main engines was controlled by a pair of hand wheels mounted on the throttle board. The hand wheels were connected to balanced type throttle valves, one for ahead and one for astern operation. The throttles were operated to control main engine speed and direction in response to orders received from the bridge by way of electrically operated engine order telegraphs.
The main engines were cross compound geared steam turbines driving twin screws. The engines were mounted side by side in the Engine Room. Total installed power was 6200 SHP. Each engine consisted of a high pressure (HP) and a low pressure (LP) turbine mounted side by side. The turbines were connected via flexible couplings to Falk single reduction gears which drove the propeller shafts.
In the earliest shipboard applications the steam turbines were connected directly to the propeller shafts. This required very bulky turbines with a large number of stages in order to obtain an acceptably low propeller RPM. By the end of World War I the use of single reduction gearing had become fairly standard. But by the late 1930s the navy had gone to double reduction gearing which allowed for much higher turbine RPM and more compact installations. Charleston’s main turbines contained numerous stages and were relatively bulky for their power output by later standards.
There were numerous auxiliaries located on the lower level. Most of these were associated with the main condensers, feed water and, main lubricating oil systems.
Charleston had what was referred to as a semi-closed feed water system with open surge tanks. The semi-enclosed feed system configuration had a relatively short life. Once the Navy decided to go to higher steam pressures, corrosion from dissolved oxygen proved to be a major problem and it eventually became standard practice to go the pressure enclosed feed systems with oxygen scavenging accomplished in deaerating feed tanks. In more recent years, use has been made of chemical oxygen scavenging agents.
When Charleston was in port in a cold iron status the Engine Room was a very quiet place. A single upper classman was assigned as the Cadet Engineer (CE). But he did not have very much to do other than ensuring that the LP drain tank was pumped out. Most of the action was in the Boiler Room. When I was assigned to this duty I would sometimes go around and start up a piece of auxiliary machinery just for practice. But you had to be careful not to make any noise that could be heard by the Duty Officer or Duty Engineer. One time there was an incident when one of the upper classman, assisted by a lower classman, managed to start up most of the major Engine Room equipment and was just about to start rotating the main engines when he got caught by the duty officer and placed on report.
When Charleston was underway during the training cruises everything changed. All watch stations, with the exception of the Officer of the Deck (OOD) and engineering Officer of the Watch (EOOW), were manned by cadets. The whole place seemed to come to life. The noise level was not very high because the major noisemakers, the turbo generators were located in the Auxiliary Room. But the space could get very hot when we were in the tropics and it was not uncommon to find most of the watch standers, including the EOOW, standing underneath a vent fan outlet to obtain relief.
In order to find something for the cadets to do when the ship was underway a number of automatic control devices had been bypassed and operations such as regulation of auxiliary exhaust pressure and feed water heater drains were being accomplished manually. The lower level men were kept busy regulating the water level in the main condenser hot wells. Coupled with the heat, these duties resulted in a very boring four hours without learning very much. I felt very triumphant when I was assigned duties as CE when I was an upper job and allowed to handle the throttles during a maneuvering watch.
The Auxiliary Room (C-2) was located immediately aft of the Engine Room by way of a water tight door located on the port side. The first item in view when entering the space was the double effect low pressure distilling plant for making potable water and reserve boiler feed water. Proceeding across the space the surge tank was located on the left and the main electrical switchboard on the right. The two main ship service turbo generators were located on the starboard side of the upper level. Numerous pieces of auxiliary equipment were located on the lower level.
Charleston was fitted with a single low pressure double effect submerged tube type distilling plant manufactured by Griscom Russell. The plant was located aft on the port side, upper level of the Auxiliary Room. The two effects were housed in separate shells.
By World War II it had become the practice to house both the first and second effects in a common shell. These plants were known as “Soloshell” types. A World War II built Fletcher Class destroyer had a single 12,000 gallon per day unit located in the Forward Engine Room. In later ship designs it became the practice to always provide at least two distilling plants on any type of ship. Starting in the 1960s the low pressure flash type plants which were much less prone to fouling came into use. Reverse osmosis type plants are being used in the latest naval ship installations.
Charleston was fitted with a 450 VAC, 60 HZ, 3 phase electrical generating plant and distribution system. At the time, this was considered to be a major advancement. Prior to 1932, all naval shipboard distribution systems were DC. A standard installation aboard World War I “four pipers” was a pair of 25 kW DC turbo generators. The only major use the navy had previously made of AC was in the electrical propulsion system of six battleships built between 1918 and 1923 and in the aircraft carriers USS Lexington and USS Saratoga which entered service in 1927. But all of these ships still had DC distribution systems.
The first naval AC ship service distribution system was aboard the USS Farragut (DD 348) Class destroyers. The keel for the first ship of the class was laid down in September 1932 and it entered service in June 1934. These ships had a 230 VAC distribution system supplied from a pair of 132 kW turbo generators. They did not have an emergency diesel generator.
By the time that Charleston and Erie were designed the decision had been made to go to 450 VAC distribution systems. A major reason for this decision was that it allowed the use of standard industrial type AC induction motors, thereby reducing procurement costs. It also allowed a significant reduction in maintenance due to elimination of commutators and carbon brushes. This required the use of closed front switchboards with no exposed electrical components. Prior to that time, most ships had live front switchboards with exposed bus bars, knife switches, and fuses. 450 VAC systems have remained standard aboard the majority of naval vessels up to this date although it has been necessary to go to higher voltages aboard vessels where the ship service load exceeds 10,000 kW.
The requirements still existed for DC power supply to some equipments and this was usually obtained from over sized DC exciters driven directly from the main turbo generators. Around this time a compact high speed diesel engine became available and the first emergency diesel generator installed aboard a destroyer was aboard the USS Mahan (DD 364) which entered service in September, 1936 at about the same time as Charleston. The generator was rated at 25 kW. This generator appears to have been a 4 cylinder Fairbanks-Morse Model 36A rated at 40 HP at 1200 RPM. A similar set was installed aboard Charleston on the Upper Level of the Engine Room, Starboard side. The evidence points to the fact that Charleston had one of the first such installations in the Navy.
Charleston’s electrical generating plant consisted of a pair of Elliot ship service turbo generators, each rated at 250 kW, 450 VAC, 60 Hz, 3 phase, .8 Power Factor. Each generator was driven by a 350 HP steam turbine by way of a single reduction gear. The generators were located on the upper level, starboard side of the Auxiliary Room and they supplied a dead front switchboard which ran across the after part of the space. The construction and operation of the switchboard was very similar to those aboard World War II built destroyers. Underway requirements could be met with one SSTG set on the line. The capacity of these generators was greater than aboard destroyers built during that era, most of which were fitted with 132 kW or 200 kW sets. This was most probably because of the requirements associated with the 6” gun systems.
Interestingly, a major proponent of AC electrical distribution systems was then LCDR Hyman Rickover who was serving as the head of the electrical system at BUSHIPS (now NAVSEA) in the late 1930s.
During underway conditions, the noise level in the space from the turbo generators was quite high. There was not much for the watch standers to do other than take readings. The distilling plant operators were required to keep track of the levels in the potable water and reserve feed tanks and ensure that the plant output was directed to the appropriate location. A single watch stander on the lower level had the duty of regulating condensate pump discharge so as to maintain the water level in the auxiliary condenser hot well.
Hotel services aboard Charleston were typical of those aboard naval ships designed in the 1930s and they would be considered rudimentary by today’s standards. Obviously the piping and machinery insulation and valve and pump packing contained asbestos, although I cannot recall any incident where we were directly exposed to asbestos fibers. The ventilation fans emitted a distinct humming noise that was much louder than those in later naval vessels. There was no air conditioning and it was common practice when underway to provide ventilation by way of wind scoops temporarily installed through the ships port holes. Obviously these had to be closed whenever the ship encountered any kind of a sea way and invariably some were found to leak causing water to slosh around in the berthing spaces. There was no central hot water system and it was necessary to place a bucket of cold water under a steam jet for routine hand and face washing. When taking a shower it was necessary to mix cold water and live steam directly by means of a pair of control valves and to get out of the way in a hurry if the potable water supply was interrupted for any reason. The toilet facilities consisted of stainless steel troughs with removable fittings that approximated the shape of a toilet seat placed over them. Flushing water came in at one end and flowed through them like a river going out the other end to overboard discharge connections above the water line. We referred to them as “Mississippi’s.”
In summary, even though Charleston and Erie had only modest propulsion powering requirements they incorporated many of what were considered to be the latest developments in naval boilers, auxiliary machinery, and electrical distribution systems in the early 1930s. It appears that they were among the first naval combatant ships with:
- Superheated steam
- Double casing boilers
- Turbine driven auxiliary machinery
- Semi-enclosed feed water systems
- 450 VAC electrical distribution systems
- Dead front switchboards
- An emergency diesel generator
- Electro-hydraulic steering
- Freon refrigeration
By the late 1930s it had become apparent that due to increased size and propulsion power requirements of destroyers that the 400 psi plants of the 1930s were no longer adequate. After 1938, the later designs made use of steam at 600 psi, 850° F generated in divided furnace “M” type boilers with superheat control, high speed turbines with double reduction gears, pressure enclosed feed water systems and “split” machinery spaces. Nevertheless many of the advances in electrical distribution and auxiliary systems described in this article carried over into ships designed and built immediately prior to and during World War II.
Despite its limitations, Charleston was an excellent ship to learn the basics of marine engineering aboard during the 1950s. The lack of automation was actually an advantage because there were plenty of underway watch stations with things for the midshipmen to do. The experience gained aboard Charleston would prove to be extremely valuable to me aboard both naval and commercial steam powered ships during a seagoing career.
George W. Stewart is a retired US Navy Captain. He is a 1956 graduate of the Massachusetts Maritime Academy. During his 30 year naval career he held two ship commands and served a total of 8 years on naval material inspection boards, during which he conducted trials and inspections aboard over 200 naval vessels. Since his retirement from active naval service in 1986 he has been employed in the ship design industry where he has specialized in the development of concept designs of propulsion and powering systems, some of which have entered active service. He currently holds the title of Chief Marine Engineer at Marine Design Dynamics.
- NAVSOURCE ONLINE
- Dictionary of Naval Fighting Ships (DANFS) Website
- Article “Alternating Current in the US Navy”, LCDR H.G. Rickover, SNAME Transactions Volume 49, 1941
- U.S. Destroyers, an Illustrated Design History, Norman Friedman
- U.S. Coast Guard Historian website
- United States Navy Destroyers of World War II, John C. Reilly, Jr.
- Naval Machinery, US Naval Institute, 1941 Edition
- Engines Afloat, Grayson, Volume II, 1999
- Massachusetts Maritime Academy Yearbooks, “The Muster”, 1954, 1955, and 1956
- USS Erie (PG 50) – Booklet of General Plans, Historic Naval Ships Association