The US Navy is seeking more merchant ships to carry a large quantity of ammunition and additional pieces of armour to the Gulf for arrival in November and December, according shipping tender documents seen by journalists.
One shows the Military Sealift Command (MSC) had been seeking a vessel to move 550 containers of ammunition and explosives from the east coast of the United States to four ports in the Red Sea and the Gulf.
"That's a big chunk of ammo'," said one shipping source who has chartered ammunition ships for the British Ministry of Defence. He estimated the vessel was capable of carrying up to 10,000 tonnes.
MSC is a branch of the U.S. Navy charged with transporting armour and military supplies for the U.S. armed forces.
A spokeswoman for the MSC in Washington, Trish Larson, confirmed the original order but said the requirement had now fallen to 319 containers.
"It's just closed (the tender) but nothing has been awarded yet. The requirement is slightly less now -- it's a fluid process," she said.
Larson declined to comment further on the quantity of ammunition being moved to the Gulf.
The vessel carrying ammunition is due to load on October 31 and to discharge at the various ports between November 19 and December 3. In shipping industry terms, the movement of 319 so-called twenty-foot-container equivalent units (TEUs) is small.
The largest freighters can carry up to 7,000 TEUs, but moving ammunition and explosives is done on a far smaller scale.
For safety reasons ammunition-carrying ships require special ventilation, temperature control and fire-fighting equipment and additional features, experts say.
The MSC confirmed it was seeking a roll-on-roll-off merchant vessel to carry 28,000 square feet (2,600 sq metres) of "rolling stock and track vehicles" from northern Europe to the Gulf in November.
The latest commercial orders bring the known number of merchant ships requested to move tanks, helicopters and other military supplies to the Gulf to eight.
That is in addition to the Department of Defense's own massive sealift capability, some of which is anchored at the British base of Diego Garcia, in the Indian Ocean, within a few days' sail of the Gulf.
Separately, the MSC had been seeking a ship to shift 197 containers of ammunition weighing some 2,700 tonnes between one unidentified Gulf port and two others, further evidence of pre-positioning activity.
MSC's Larson said a decision had now been taken to move the quantity on a government-owned as opposed to merchant ship.