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Precis File
SHIP NAME: Tamano KEY: NUM. ENTRIES: 6
source OSCH
type A
volume 2380B
material No 6 Fuel Oil
dead
link

In the early morning of July 22, 1972, the tanker Tamano grounded on Soldier's Ledge in Casco Bay, Maine, tearing a 20-foot hole in a starboard tank. The tanker continued to its anchorage in Casco Bay before the leak was noticed. The tanker was carrying 550,000 barrels of No. 6 Fuel Oil, 2,380 barrels of which spilled into Casco Bay. The Captain of the Port (COTP), Portland, Maine, was the On-Scene Coordinator (OSC) for the incident. The response ended on October 16.

No. 6 fuel oil is a heavy product with an API gravity that ranges from 7 to 14. Due to the prompt action of the vessel pilot in getting the tanker boomed most of the spilled oil was contained. Of the 2380 barrels of oil that leaked from the vessel, 1670 were recovered from within the boom. Oil impacted 46 miles of mainland beaches. All the islands in Portland Harbor were oiled.

Transfer of oil from the ruptured tank began immediately upon discovery of the leak. The pilot of the tanker notified Sea Coast Ocean Services (SCOS) at 0215 that the vessel was leaking, and that booms were needed. SCOS responded immediately with booms and barges, and had the bow boomed by 0530. The OSC activated the Atlantic Strike Team (AST), and conducted overflights. The tanker was completely boomed by 0930 on July 22, and the situation appeared to be under control. On July 23, it was discovered that the oil had moved under the boom and was surfacing some distance from the tanker. SCOS had insufficient response equipment available to handle the spill; the OSC contacted Texaco Inc., which had chartered the vessel from the Norwegian owner, Wilh Wilhelmsen. Texaco denied responsibility but agreed to temporarily fund the cleanup operations. The OSC hired more cleanup contractors, including SCOS. Skimming of the contained oil, and skimming of oil outside the containment boom began. Hay spread on the uncontained slickproved effective as a herder and absorbent, but it clogged the skimmers. Beach cleanup began on the mainland and island shores. Oiled hay and seaweed on the beaches were removed manually. Oil recovery operations lasted two weeks.


source SIS83
type D
volume
material
dead
link

fuel oil, 20 ft gash abt 8 inch wide in No 1 stbd wing tank, 1968 blt. This is a typical damage description. By far, the most important number for damage below the waterline is the highest point of the damage. It is almost never recorded.


source LINK
type L
volume
material
dead
link http://academic.bowdoin.edu/faculty/D/dpage/html/oilspill.html

source MIT79
type D
volume
material
dead
link

Scraped buoy and edge of channel after picking up pilot. Buoy possibly out of position.


source EPA 430/9-75-018, Tamano Oil Spill In Casco Bay, pub: December, 1975
type A
volume
material
dead
link

At approximately 0120 EDT on july 22, 1972, the 810 ft Norwegian tanker Tamano, owned by Wilh Wilhelmsen of Oslo, and under charter to Texaco, Inc, grazed Soldiers Ledge in Hussey Sound, Casco Bay, Maine, tearing a 20 ft by 8 ft hole near the turn of the bilge in the No 1 starboard wing tank, which contained approximately 12,000 barrels of No 6 fuel oil of the low pour variety. The vessel with a maximum draft of 58 ft registered a mean draft of 44 ft on approaching the Sound. Soldier's Ledge lies at 40 ft (MLW) marked by a lighterdr buoy. The accident went unnoticed until 0200 when Tamano anchored in the Hussey Sound Anchorage, 2600 yards north of Long Island, Casco Bay, and oil was seen escaping from the beneath the hull. The pilot immediately notified Sea coast Ocean Services, a local clean up contractor. USCG personnel arrived on the scene at 0400 and by 0930 the ship was completely boomed.

This action appeared adequate until [1600] 23 July 1972 when Coast Guard overflights revealed that oil from beneath the Tamano hull was escaping to the surface beyond the booms. The OSC then called contractors from the Boston area for additional booms and skimmers. Auxilary pumps were called in to assist Tamano in transferring oil from the damaged tank to other tanks, and skimmers commenced removing the oil from within the booms. The damaged tank was cleared of cargo by 25 July. Oil within the booms was removed and discharge of cargo was completed on 3 August 1972. The Tamano cleared port for drydocking on 4 August 1972.

The initial report estimated the official loss of oil at 40,000 gallons. A later report stated that 100,000 gallons of oil escaped with 70,000 gallons of good oil being recovered. Due to the inaccuracies in estimating the amount of oil escaping into the environment or recovered in removal operations, the quantity of oil lost could be even greater than the reported 30,000 gallons.


source CTX
type D
volume 100000G
material
dead 0
link

CTX Director Jack Devanney was at this spill the next morning and recalls that the spillage had stopped, and then restarted when the ship started pumping out the non-damaged tanks, lifting the ship and destroying the hydrostatic balance in the damaged tank. However, in no offical account of this spill of which CTX is aware is this mentioned.

The OSCH account is clearly wrong is saying that the ship started pumping out the ruptured tank. With a 20 foot gash all this would have done is move sea water around. The EPA report is revealing in that it refers to salvage pumps only after the second spill. In any event after hydrostatic balanced had been achieved, there's no way new spillage could have started unless the ship was lightened. CTX believes that the new oil discovered on the 23rd was the result of mishandling hydrostatic balance.

The EPA report is valuable in that it contains a rough idea of the height of the damage, tells us the volume in 1S, and the ship's draft. Unfortunately, "near the turn of the bilge" is not very specific especially for a No 1 wing tank. But it is pretty clear that the damage was quite low in the tank. Since the draft is put at 44 feet, and Soldiers Ledge is put at 40 feet at MLW, the damage was probably confined to the bottom 3 or four feet. (The ship must have grounded at near low tide.) We need to know the innage in 1S to compute the hydrostatic outflow if the crew had done nothing. Of course, if the crew had quickly trimmed and listed the ship toward the damage, there would have been very little outflow.

The EPA report is a bit misleading when it talks about inaccuracies. It's true that the amount recovered is very hard to measure. But the amount lost from the tank is not. The ship (and presumably the USCG) should have been able to measure the amount lost from the tank in both the first and second spills to within a few tens of barrels.

We need depth of penetration, but based on 8 inch width number, double hull almost certainly would have avoided a spill. Of course, the flooding of forward wing ballast tank may have generated its own problems, depending on the topography and the state of the tide. Need more data, most importantly, the innage in 1S.