The following day PTs engaged in the invasion as planned. Two minesweepers were sunk and the PTs effected a quick rescue of the survivors. Although no opposition materialized, these boats were operating in full daylight with in a few hundred yards off the enemy coast prior to Naval bombardment of enemy shore-battery positions.
The mission of the US PTs after h-hour D-Day was that of maintaining a picket line, called the Mason Line, at the western end of the assault area. This line was established as an inner defense against possible infiltration of E-boats into the convoy unloading area. This line was 6.5 miles long bearing 240 degrees true from 49 degrees, 32 minutes, 30 seconds North - 01 degree, 06 minutes, 55 seconds West to the French Coast. An average of nineteen PTs were kept on this patrol line at all times. The average length of duty on the Mason Line was one week although certain boats maintained a constant patrol for three weeks without relief. Mechanical failure or extensive hull damage were the principal reasons for boats being forced to return to the Portland Base. Fuel and water were provided by small barges and provisions were secured from other Naval craft in the area.
Special duties were assigned to the boats on the Mason Line. These assignments included dispatch work, that of extinguishing surface flares dropped by enemy aircraft as guides to the unloading area for their bombers, rescue work, destruction of floating mines and "screening" larger craft by running ahead of them over possible mined areas.
Two and three boat patrols were carried out north-west of the Mason Line during this period. A northern limit of 49 degrees, 40 minutes North was set for these operations due to the proximity of another friendly task force with a lack of information as to their movements and the use of different radio frequencies. As a result of the above mentioned lack of co-ordination of operations, a short action between U.S. PTs and British MTBs occurred on 13 June 1944. Fortunately no serious personnel or material casualties resulted.
On occasions, PTs were used to draw enemy shore battery fire in order to establish the exact location of these shore batteries. No personnel casualties resulted from these missions although one boat suffered engine damage as a result of a near miss by large calibre enemy fire.
Boats were nested at finger piers provided by Coastal Forces, U.K. At the repair unit an electric-hoist Marine railway was furnished with track facilities for two boats. Several Quonset huts were erected and used for administrative offices, post-office G.S.K. and squadron offices. A small dispensary and office space for our navigational department were made available in the Coastal Forces headquarters building, adjoining the marine-rail shed. The torpedo circuses shared the torpedo shop used by the Coastal force. The marine-rail shed had ample space to house a tool shed. stockrooms, ordance-shop as well as the entire repair gear of the E-ll unit. A floating dry-dock, used for changing struts and screws as well as for minor hull repairs was located about a quarter of a mile distant.
"Tent City" built on the site of old gun butts and gun range, had 99 16' x 16' tents, in which were housed approximately 800 officers and men. The site also included a sick-bay tent, two wash and shower buildings, two storage tents, a laundry shack, a 1st Lt.s office, a small hut for drying laundry, two food storage tents, two large tents - one used by officers and the others by chiefs as mess-halls, a large 71' by 31' combination mess-hall and movie-hall and a concrete-decked galley building. Adequate during the summer months, "Tent City", originally expected to be used for several months at most, became a rugged living spot when the wind and rains started to beat in from the Channel during the fall. At that time, plywood decks and small coal stoves were added but the strong winds frequently blew down tents and the coal stoves proved to be a fire hazard. Finally, toward the close of October, PTs were given the U.S.S. Southland, an ex-Chesepeake Bay excursion boat, as living quarters for most of the men and officers. A few officers had found quarters at the Portland Roads (combination hotel and pub) and at another nearby pub. Several others found make-shift quarters in a sheet-tin garage near "Tent City".
A floating drydock was towed over to Cherbourg and all but the most extensive hull repair jobs were conducted by the Cherbourg repair unit. Although an ideal location for PT boats existed, this berthing space, a flooded dry-dock, could not be used because the waters had not been cleared of German mines and the area of booby traps. The former E-boat torpedo shop as well as enemy's engine repair shops were used by the boats operating from here and a radio shack and briefing office were set up in the main French Marine building.
Lt. H.J. Sherertz, USNR, Commander of RON 34, commanded the Cherbourg Base during the time his squadron was assigned to Task Group 125. Later an alternating set-up was arranged and boats from RONs 30, 34 and 35 divided five-day patrols and ready-boat assignments at the Cherbourg base.
RON 30, which has been assigned to Commander Ports and Bases France, will use Cherbourg as its main operational and repair base.
10-18-2000