LIFT-OFF

 

By Bob Halstead

I have a theory that a diving instructor can teach diving only a limited number of times in his/her lifetime. So when my wife Dinah and I started our own dive school in Port Moresby in 1977 we were careful to avoid “burn-out”.

We closed the dive school for a couple of months around both Christmas and Easter, cruised our dive boat Solatai to Milne Bay, and ran adventurous Scuba Safaris for qualified, experienced divers. These adventures were all about exploration, and discovery of new reefs, shipwrecks and marine creatures.

On one of our Scuba Safaris we were looking for the wreck of a Lockheed P38 Lightning aircraft that a friendly villager had told me about. An old man remembered where the airplane had ditched. Within a few minutes we had found the wreck lying in 27m on silt and sand with its nose, potent with guns, almost touching a reef slope. I recovered the brass call sign from the cockpit and this identification enabled researchers to find out the history of the aircraft.

On November 27th 1943 Pilot Alex Illnicki had been on a patrol mission to Salamaua. On the way back he made a navigational error and ended up well down the Louisiade Archipelago. Attempting to get to Alotau he ran out of fuel and ditched the Lightning in a bay on the north Coast of Basilaki Island. He survived, but, as far as I know, no one had seen the aircraft again until we came along.

When I first dived the wreck it was obvious that both propellers were missing, and I thought this strange. Could someone have dived the wreck before us and salvaged them? It seemed unlikely. Many years later, on our live-aboard dive boat Telita, an aircraft enthusiast explained that, on the P 38 Lightning, the propellers were attached to the engine via a gearbox and this could be a weak point. They probably broke off when the aircraft hit the water.

We guessed the flight path and took a compass reading. Diving to the aircraft’s tail, we fastened the end of a ball of string, and headed off on the compass course. Just as we ran out of string we could see both propellers half-buried in the silty sand. It was time for my lift bag.

One piece of equipment I always carried on board was a lift bag. This looks like a miniature parachute. It can be used to move moorings, and salvage heavy objects, and it was particularly useful if the anchor winch broke down and we had to get the big anchor and chain off the bottom before hand-hauling it aboard.

Lift bag technique seems easier than it is. You take the bag down to the object to be salvaged and tie or shackle it on. You make sure the venting valve on top is closed, fill the bag with air from a spare tank that you carry down and, if you have judged correctly, you will have lift-off.

Things that can go wrong include getting tangled in the lift bag ropes and shooting off to the surface with the salvage. Or neglecting to make sure the boat is not directly overhead – of course if the boat sinks, and is small, you may be able to use the lift bag to recover it. See? These lift bags are really handy.

A 200 litre lift bag (think the size of a 200 litre fuel drum) will lift up to 200 kilograms so you are working with big forces. If you do lift something to the surface you have to be careful to secure it as any air spilling out of the bag may cause the whole lot to plummet back to the bottom. Again, you must make sure you are not tangled in the bag and ropes.

Years ago a diver in Rabaul PNG died while salvaging brass shell cases from a war wreck in deep water. He was caught in his lifting gear, which leaked at the surface while he was trying to secure it, and he was dragged to the bottom before he could get his regulator back in his mouth.

My lift bag was big enough to carry the weight of each propeller but they were both well stuck in the bottom. So with the bag full we rocked the first one to break it free. After a couple of minutes it started to move and then lifted, spiralling and shedding silt as it flew up to the surface. That was an amazing sight.

We towed it over to the wreck and, using the vent, deflated the bag so that each propeller in turn was lowered close to its engine. By partly inflating the bag we could then manoeuvre each of them into position.

One propeller sits upright looking as if it is still attached to the aircraft, and the other lies right in front of its engine. Thanks to my trusty lift bag, visiting divers can appreciate seeing this wonderful aircraft wreck complete again. With a little bit of imagination, it looks almost ready to fly.

 

November 2008

 

 

 

 

 

 Posted by at 7:31 am