« ed a y . Mr. Joe B. Sanders — Subject: \ ? Taongi Atoll - Construction and Support Requirements 30 January 1957 Page 3 ' a Harbor Facilities. For both maximo and minimum requirements a channel 300 feet wide with a depth of 20 feet at mean low water is proposed. ‘The probable location is in the area south of Pokaakku Island or in the southwestern reef. The exact location will be determined from the site survey. For purposes of estimating cost we have assumed the length of the channel excavation to be 1000 feet. . A mole 75' x 150' long is proposed on the lagoon side for the maximum condition only. The entrance channel and the approach to the mole contemplates the use of LSTs. It is assumed that the scientific barges will be outfitted at site Elmer and moved to Taongi in an LSD or under tow by a seagoing tug. Presently we contemplate that these barges will be taken in tow by LCMs and LCU off the entrance channel for movement into the lagoon. The feasibility of such an operation will require further study of current and sea conditions in the channel and in the operating area off the Atoll. Construction Equipment. The cost estimates hereinafter provided cover both construction and operation equipment for the maximum and minimum scope contemplated. The equipment planned is that considered essential for the construction of the scientific stations, camp and the other service and support facilities. Any changes in the magnitude of the contemplated scope of work will be reflected in a change in equipment requirements. ‘ Marine craft requirements will depend entirely on the modus operandi of gaining access to the Atoll. For planning purposes we assume approximately 4 LCMs, 2 LCus ; and 6 DUKWs will be required for both maximum and minimum conditions. Foundation Investigations. We contemplate an early exploration party to obtain drilling core records and samples of the island soil and coral cap and the reefs for test and evaluation at the Elmer Laboratory. Surface and Air Support. It is assumed that an LSD will be made available during the early construction period. This type vessel can carry loaded LCMs and LCUs with which we have assumed the first landings on the southwestern reef can be made. The use of an LST for these landings does not appear feasible. The water drops off to great depths just off the reef and it is doubtful that an LST would be able to use its stern anchor. The LSD type vessel is the best suited to act as the mother ship for our craft during the early construction period. We do not know whether an anchorage to seaward of the Atoll exists or whether LSD operations will have to be accomplished with the vessel lying to. The docking facilities of the LSD make it very suitable for picking up our craft rapidly in case of bad weather. We will need the support of the LSD until we can make sufficient progress on the channel to permit passage of our landing craft. Thereafter we will require continuous and independent support of an LST. The support of seaplanes for emergency evacuation or other emergency needs will be required until the airfield is constructed. On completion of the airfield we assume that airlift support will be similar to that provided on the Eniwetok-Bikini run during Redwing.