The first keel laying on Sun Ship's new shipbuilding slabs in the North Yard, took place on 04/07/1975 when the Sun 800, the Yard's 800 ton floating crane, lowered a 511-ton inner-bottom section of Hull 668's stern on 'A-Slab'.
#706.7505.03b (Courtesy of SSHS)
Original Name:S.S. ''Tonsina'
Note 1: If anyone has any additions or corrections to this page, please contact us via the email address on the site's opening page.
The 'Tonsina, first of two 120,000-dwt tankers was built for time charter to SPC Shipping, Inc., a subsidiary of the Standard Oil Company of Ohio (SOHIO).
The 'Tonsina' is a Sun Ship designed 'Ecology" class tanker incorporating several environmental protection and safety features such as; a double hull, an inert gas system, fixed cargo tank cleaning equipment and a collision-avoidance system. Oil/water separators clean the bilge water and cargo tank washings before they are discharged overboard. A sewage storage and treatment system provides discharge of clean effluent where permitted, or holding where not permitted.
The vessel's 18 cargo tanks can carry about 840,000 bbl of crude oil at an operating draft of 54 ft. Four high-capacity pumps unload the cargo tanks in 12 hours. Taking into consideration that the tanker will carry crude oil from Valdez, just below the Arctic Circle to Pacific Coast ports, the designers used high-strength steel in the upper deck plating and sheer strake areas for greater resistance to structural cracks in cold weather service. Other features include engine room automation, with control of engine speed and direction from the bridge, air conditioned crew quarters, and an elevator linking the four superstructure decks with the engine room. Two Babcock and Wilcox main boilers provide steam flow at 242,000 lb/hr, 880 psig, 955 F, to the General Electric main engine-a 30,000-shp cross-compund turbine-driving a 26'9" diameter, 5-bladed propeller at 95 rpm through reduction gear.
The ship was constructed in two halves with the stern being built on 'A Slab' in the new North Yard facility and the bow being built on the inclined-No.6
shipway in the Central Yard. The bow section was launched on 6/8/77 and was put on the 'A' section of Sun Ship's 2-section #4 Dry Dock. The stern section was transferred from the flat 'A-Slab' by the use of two 'Hydranautics' hydraulics units pushing the ship from the slab onto the 'B' section of #4 Dry Dock. With the 'meeting ends' of the hull overhanging the drydock sections, ballasting would bring the two sections into vertical alignment and use of strong-backs and turn-buckles would pull the two sections together for final welding of the bow and stern sections together.
The stern section of Hull 668 is shown under construction on the 'A-Slab' of the new North Yard shipbuilding facility.
#ssl1302005a (Courtesy of SSHS)
View of the bow section of Hull 668 being constructed on the #6 inclinded shipway in the Central Yard.
#668.3885.05a (Courtesy of HML)
View of both sections joined on Sun Ship's #4 Dry Dock
#668.3885.16a (Courtesy of HML)
'Tonsina' underway down the Delaware River.
#ssl_1978.06.7c (Courtesy SSHS)
Shown as the 'Kodiak' c: 2012
Shown as the 'Eagle Ford'. off of Marcus Hook, PA, Thanks to John Curdy for letting us know that she was on her way upriver. 03/29/2016
#443_68_13c (Courtesy Dave Kavanagh)
Shown as the 'Leo', this picture showing bow to stern, Stbd side of ship aground in Gadani, PK to be scrapped. c: 2016
#315.32.01-a (Courtesy Fred E)
The following pictures, while not from the Hull 668 collection, are representative of the process of transferring a ship/ship section from the building slab to the drydock. There are 2 Hydranautic hydraulic units, one on the port side and one on starboard side, that consist of 1) a 'sled' with operators controls-hydraulic pumps, valves and a hydraulic tank, 2), the middle unit has clamps that grip the steel beam that is secured to the concrete base and are pressurized to keep the unit from moving backwards when the rams are being extended and 3) this unit has the four hydraulic rams that will push the ship in 36" increments per cycle. Each unit has one operator and they are in constant communications with one another as each movement has to be synchonized to apply equal force to either side of the ship when extending the rams.
Transferring a ship from the building slab to the dry dock
One of the two 'Hydranautic' units that will push the ship off the slab and onto the drydock,
#5353.06a (Courtesy of HML)
Port side unit from the view of the operator. You can just make out the rollers (2 sets on each side) beneath the unit. These rollers supprt the weight of the ship during a transfer. In this view, the ship is haflway onto the dry dock.
#4643 (Courtesy of HML)
This view of a 'Transfer' shows the stern section of a ship that has been completely transferred from 'A-slab' onto No.4 Dry Dock's 'B' section. Keep in mind that the dry dock must be level at all time during the transfer. This is accomplished by the use of computer controlled ballast pumps. In addition to the tide levels changing approximately 7', the weight of the ship as it transfers on to the dock has to be compensated for.
Note: Only dry dock 'B' was equipped with a computer controlled 'Tide Compensation System' which would add or remove ballast from specific
ballast tanks in the dry dock to insure that the dock stayed level. Later when entire ships were needed to be transferred to/from the dry dock,
Section 'A' had to be operated manually and this method worked fine for transfer of larger ship sections.
#008.01.14 (Courtesy of Jan Karlsen - 38 Dept.)
#1: Hydraulic tank, pumps, valves and operators controls are
located in this 'sled'.
#2: One of four (4) hydraulic rams on this 'sled' will push the
ship forward in 36" strokes.
#3: Hydraulic clamps are located on this 'sled' which will
clamp the 'sled' to the steel beams secured to the
concrete below so the sled will stay stationary when the
rams are extended.
#4 View of the beams and rollers on which the ship will
move towards the dry dock.
In Remberance of Our 'Tonsina'' H-668 and her 38 years of honorable service:
“The launching of a ship, be she a twelve-foot dinghy, ocean-going liner or great battleship, is a solemn occasion.
At this moment the future looms nearer, unseen but not unfelt; and pride of workmanship becomes humbled before the immensity of the challenge to mighty elements and a fate beyond man’s control.
Man-the-Builder has toiled for days, months or even years to shape this new and shining tool. Now it is to be committed to the sea, to a hidden destiny; and Man-the-Seafarer must put forth in her to test the mystery of oceans and to give her the life for which she has been cunningly made.
No one can tell if that life will be short or long, a maiden voyage wreck or years of tramping the seas to an honorable discharge in the shipbreakers yard."
Note: These words were borrowed from Peter Shankland and Anthony Hunter's fabulous
book 'Malta Convoy', published in 1961, which, in part, describes the critical role our tanker 'Ohio'
played in the success of that convoy in World War II. Please see our page on S.S. 'Ohio' Hull 190