USCG HISTORY: On this day, January 1, 1958 -The Coast Guard ceased listening continuously for distress calls on 2670 kilocycles. Although the countries of the world had agreed at the Atlantic City Convention of the International Telecommunication Union in 1947 to use 2182 kilocycles for international maritime mobile radiotelephone calling and distress, the Coast Guard had continued listening on the old frequency until the public had had sufficient time to change to the new one. --------------------------------------------------- This page provides more detail about the U.S. Coast Guard Cable ship Pequot during World War II. In today’s military, communication between ships, and from ships to shore, is sent by satellite in quick encrypted digital bursts of data from computers in a matter of seconds, a far different world than how the Pequot had to operate. Even with the two-way radios of the time, signals were often garbled or lost due to weather or equipment failures. During periods of radio silence, signal flags and pennants were run up the mast to communicate between ships, sailors on deck used semaphore flags, and especially at night, signal blinker lights using the “dash dot” language of Morse Code got the job done. Our main page for the USCG Pequot provides extra details about the ship, its crew, its purpose as well as links to our other Pequot pages. Research and design by by Chip Calamaio and Richard Walding. COMMUNICATIONS The images below show sailors using semaphore and Morse. As well, thumbnail images of pages from the 1940 Bluejackets Manual are shown. Click these Bluejacket images to see an enlarged view. Note: In the enlarged view of the Communication Training chart below, you will see handwritten notes by Sailor Roger Calamaio. We can speculate that his updates to the code alphabet, from bootcamp in 1942, may have been made, by the military, to confuse the enemy. Although still in use, in the 65 years since the Pequot sailed, the Military Code Alphabet has changed. For example, today A is Alpha and Z is Zulu. The Pequots Visual Call Sign was W-58 which meant that the W, 5, and 8 flags would be flown from the mast to identify her to other ships. In addition to having the universal Red to Port and Green to Starboard running lights, as a cable ship operating in international waters, the running lights added to Pequot’s mast consisted of an upper and lower red light with a while light in the middle. Per the regulations detailed in the Coast Guard’s 1943 “Nautical Rules of the Road” directives when Pequot was stationary and not underway the standard red and green side running lights were to be turned off as a signal to other ships that Pequot was not under power and unable to get out of the way. For cable ships in international waters during daylight hours of operations two round red balls separated by a white diamond pennant are flown from the ships mast which tells other vessels: Keep clear Im engaged in underwater operations. Despite these road rules we can assume that during much of her WWII travels along the Eastern seaboard, especially at night, that Pequot ran dark to avoid detection by U-boats. THE RADIO WAR Although primitive by today’s standards radio communications of many types played an intense role during WWII especially in the Battle of The Atlantic. Like all Coast Guard ships, the Pequot was equipped with a variety of high and low frequency radio receivers and transmitters. Most radio traffic was enciphered. The messages came in 5-character groups of numbers and letters mixed together. Radiomen had no idea what they were receiving. Transcriptions would be passed to an officer on the bridge who would do the decoding. The Mill. All communication had to be accurately documented and logged and a custom communications typewriter called a “mill” was used by most Radiomen. It had special keys to distinguish between similar characters such as the numeral 0 and the letter O. The mill had a slashed zero Ø so there was no confusion with a capital O, It also had a #1 key, which other typewriters of the era didn’t, a small “l” was normally used. The mill was designed to eliminate having to use the shift key as much as possible for speedy radio transcription. When at sea short range two-way voice radio was permitted using a the Talk Between Ships, or TBS system. This was only permitted when ships were in very close proximity to each other. At night, when visibility was greatly reduced, and when submarines or other enemy vessels might be within range, use of very high Frequency or VHF radio was strongly discouraged. There were many cases where the German U-boats and surface ships would try to bait Coast Guard and Navy convoy escorts by sending out false distress calls. Other basic communication was also completed by the dash and dot alphabet of Morse Code by tapping hand transmitters. Coast Guard Radiomen had to be expert at notating incoming Morse Code transmissions quickly and accurately. Lives often depended on correctly receiving the distress calls from cargo ships after U-boat torpedo attacks on the Eastbound and Westbound convoys. The Pequot’s Radio Call sign NRFQ was designated by the Office of Naval Operations for all US Navy and Coast Guard ships. In addition the Pequot was equipped with its own intercom communication system that was used between the bridge and the ship’s main operational areas such as the engine room, the radio room, and the two rear mounted gun positions. Radio Direction Finding. Shortly after the Army mine layer General Samuel M. Mills was converted to the cable laying ship Pequot she was equipped with a first generation radio direction finding (RDF) system or Radio Compass. This can be seen on the photo below (right) as the distinctive diamond shaped rotating antenna on top of the wheelhouse. It is not evident on the earlier photo to the left. This technology, which was first deployed by the Coast Guard in the early 1920s, enabled the ship’s radio operator to get a compass bearing fix on the source of a ship or shore radio transmission. Not only was this an aid to navigation, but it enabled ships to locate each other at sea and during the war determine friend from foe. HD/DF or Huff-Duff. We see that by 1944 the diamond shaped RDF antenna was replaced by a circular loop antenna (see left-most photo below). This indicates that Pequot was equipped with the newly developed High Frequency Direction Finder (HF/DF) system or Huff-Duff as crews liked to call it. This new system was vastly superior and more accurate than earlier systems and enabled Pequot to not only obtain bearings from shore stations and more accurately navigate the rocky North Atlantic coast, but also to locate other Coast Guard and allied ships, as well help keep a keen ear out for transmissions from U-boats. Radio direction finders and Huff Duff technology were used extensively by both the German U-boat commanders and the ships of Allied convoys during the battle of the Atlantic. Each side did all they could to locate the position of their adversaries radio transmissions. The Germans used RDF to locate convoys and moved U-boats into position for torpedo attacks, and Allied escort ships used Huff Duff readings to set course bearings to chase down and depth charge wolf pack submarines. A June 7th 1942 “Request for Work Authorization” we’ve obtained from National Archives signed by the Chief of the Coast Guard Radio Engineering Section, Irving L. Gill instructs the First Naval District Boston Radio Engineering Maintenance group to “Remove present CGR-17-B direction finder and install a Direction Finder (DF) Type RDSC-121 complete with gyro-repeater.” We believe this equipment change was the Huff-Duff technical upgrade we see evidenced in the WWII era photos of Pequot. In 1945 the Pequot was equipped with SO-1 microwave search radar which had a maximum reliable range of 13.5 miles to see aircraft at 500 elevation, it could see a battleship at 23 miles, and a destroyer at 14 miles, but it could only distinguish a surfaced submarine at a range of 1 mile. It had a resolution of 200 yards and at 4 miles was accurate to about 60 yards. It enabled Pequot to see ships, planes and coastlines in all types of weather and at night through the use of a Plan Position Indicator (or PPI) scope. Contacts picked up on the PPI scope would immediately provide officers on the Pequot’s bridge the range and bearing of aircraft and ships in the area, as well as verify Pequot’s location along the rocky shores of New England, Nova Scotia and Newfoundland. Although a short range device, the addition of SO-1 helped Pequot see in the dark and greatly increased the ships safety. RADIO GEAR Since first serving as the Army mine planter the General Samuel M. Mills and until being scrapped as the Pequot in 1947, the ship’s radio room went through numerous generations of equipment upgrades. As technology improved and the ship’s mission changed, existing transmitters, receivers, walking talkies, and direction finding gear were routinely upgraded to the latest technologies. Work requests and maintenance documents from Boston’s First Naval District Coast Guard Office obtained through National Archives provide a snapshot of some of the changes and alterations made to Pequot’s radio equipment during WWII. February 16th 1943 Per a December 1942 radio log correction we see that a TPC-119 Transmitter was installed on the PEQUOT. This was a portable emergency radio transmitter often installed in life boats. We speculate that rather than it being used as a life boat radio it may have been used for portable communication between Pequot and the crews out in the dory and launches who were marking loop cable installation points. March 15th 1944 A TCE Transmitter along with T-6-A, and T-4 equipment was removed and a TDE and T-106 transmitter was installed. During this same period of maintenance an RBO Receiver and its associated alternator were installed “in the ward room aft. January 19th and 29th 1944 Within the 1st Naval District Coast Guard Office in Boston a series of memorandums from the Assistant Chief Operations Officer detail how the Pequot was provided with portable radios including four SCR-536 “Handy Talky” units specifically for operational testing purposes and to provide a comparative test between the SCR-536 and a Model TRP-114 radio. Four TRP-114 systems were assigned to the Pequot and two were loaned to the Army for experimental use. “The purpose of this test is to determine the suitability of the SCR-536 equipment for providing communications with ships’ boats and to determine the relative merits between this equipment and the model TRP-114 equipment which is now undergoing tests on this vessel.” “It is desired that the DCGO 1st Naval District be furnished four model SCR-536 equipments, operating on 2670 kc.(kilocycles) and that this equipment be tested on the PEQUOT under actual service conditions in conjunction with the model TCO-2 equipment, which was recently installed on this vessel.” CABLE DETECTION EQUIPMENT In addition to laying down indicator loop, communication and power cables the Pequot spent a great deal of time pulling up damaged cable and repairing it. Often anchors from cargo ships who were off the East coast preparing for convoy runs to England and Russia would snag undersea cables and damage them or break them completely. By towing a grappling hook on the end of a rope and dragging it along the seafloor the Pequot would retrieve dysfunctional and broken cable, haul it to the surface, then repair damage or splice the ends of broken cable back together. A very tedious and time consuming operation when sitting stationary. Quartermaster Lou Carhart tells us that Captain Lars Sande had the uncanny ability to snag underwater cables, “The old man was pretty good at that. Every time he came up with a cable on the first try.” To help things out and to pilot test some 1940s state-of-the art technology the US Navy Bureau of Ships (BUSHIPS) provided the Pequot “Submarine Cable Locating Equipment” which they had “recently developed, and now have under manufacture.” Among the Pequot records we’ve obtained from national archives is an October 1st 1943 communication to Captain Sande from the Coast Guard District Office in Boston informing him that the Bureau of Ships would be delivering a cable locator directly to the Pequot. “This equipment is a modification of a similar device made up experimentally a few years ago in the Coast Guard Cable Laboratory. It consists of an interrupted tone source which is connected to one or more conductors in the cable, and a pickup device with associated amplifier, which is towed across the cable area. Its purpose is to locate and identify an individual cable and reduce the time required for dragging.” We believe that this unit may have been a Model OBB Cable Detecting System. BUSHIPS offered a number of these devices to the Coast Guard for use on cable repair vessels which frequently laid and repaired underwater cables. In addition to delivering one of these units to the Pequot at Constitution Wharf in Boston, one was provided to the 12th Naval District Depot Coast Guard Telephone Repair Shop at Yerba Buena Island, in San Francisco, California and to the 13th Naval District Coast Guard Telephone System Office, in Port Angeles, Washington. “Shipment will be accompanied by an instruction book covering its operation. It is suggested that it be tried out whenever the necessity arises for locating a Navy or Coast Guard cable in connection with repair work. A report is requested of the results obtained in the operation of the equipment, its desirability for general issue, and any recommendations for its modification that may appear desirable.” Detailed Specifications on the OBB Cable Detection Equipment can be found in the 1946 Catalogue of Naval Electronic Equipment: hnsa.org/doc/ecat/cat-0814.htm see more at: indicatorloops/usn_pequot_communications.htm
Posted on: Thu, 01 Jan 2015 22:07:12 +0000
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