The boys with the bang!

Written by Simon Brown Tuesday, 27 January 2009 00:00

Fixing explosives to unexploded bombs on the sea bed All photos: Simon Brown Boxes of demolition charges containing plastic explosives Royal Navy clearance diver inspects a 500lb bomb Strapping plastic explosive to an unexploded bomb An unexploded 5.5in shell Preparing the safety fuse The fuse end of a 5.5in shell A 2lb charge is secured to the shell The 5.5in shell and demolition charge shower earth and debris into the air An officer inspects the crater after successful demolition work.

Lying on the sea bed was a rusty tube, nearly 2m long. This find wouldn’t fit in the goody bag, but then again, I’m not sure anyone would want it sitting in their garage. The tube was a 500lb bomb, packed with enough high explosive to send me to the great dive site in the sky. The only comforting thought I held was that if the bomb were to explode there and then, I wouldn’t know much about it.

I was joined on the sea bed by a Royal Navy bomb disposal diver. He set to work strapping the demolition charge onto the casing of the bomb. Perhaps the bomb had played some small part in history, but in a few minutes, if all went to plan, it would be history. With all that explosive power sitting on the sea bed, we had decided to forgo the traditional three-minute safety stop. And while I normally endorse defensive diving, I wanted to get out of the water at the earliest possible opportunity.

On the northwestern tip of mainland Scotland, just east of Cape Wrath, is a tiny island of solid rock known as An Garbh-eilean, or Garvie Island. Few people have heard of the island, and even fewer have dived the surrounding waters. But then again, few would want to: Garvie is Europe’s only air-to-ground bombing range where the RAF flies practice runs with live 1,000lb bombs. The entire Cape Wrath region – an area of more than 200 sq km – is a live-fire range, and it’s not just the RAF that carries out drills here: the Navy practises ship-to-shore bombardment, firing 4.5in shells from up to 19km away. About one in ten items of ordnance fired at or dropped on Garvie Island fails to explode, and the job of tidying up these hazards falls on the shoulders of the Royal Navy’s Northern Diving Group.

The Navy doesn’t do anything by half measures, as demonstrated by its 700-tonne dive vessel, RMAS Tornado. Equipped with its own recompression chamber, it has facilities the best liveaboards can only dream about, but on the day of my visit there were enough explosives piled on deck to send it skyward. It was plastic explosive, commonly referred to in bomb-disposal circles as ‘bang’. I wondered aloud what would happen if the pile of explosives went off, and the senior NCO quickly pulled me up on the correct terminology. ‘Go off? Go off? Food goes off... explosives initiate!’ he said, assuring me that the boxes of bang on the deck were relatively safe. It takes a detonator to make bang initiate.

The Tornado took an hour to steam from Loch Eriboll to Garvie Island. En route to the search area, the officer in command of the operation briefed us about what we could expect to find and how to identify a live bomb from a practice round. Any bomb painted blue was a practice round and wasn’t worth bothering with. Anything painted green, particularly anything with gold rings painted on the nose, would need a return visit for demolition.

Another clue to identify a live round was the presence of a fuse, as practice rounds do not have them fitted. In times of war, an unexploded bomb causes no end of problems for the enemy, and the designers of these weapons build anti-tamper mechanisms into the fuse. An unstable, tamper-resistant fuse is not the friend of the bomb disposal diver.

I rolled backward off the RIB into the water, 20m from Garvie Island, and descended through incredibly clear water. As I knelt on the sand, the sunlight filtered thought the green water and I briefly admired the scene, but I wasn’t here to shoot art. This was the search phase of the operation, swimming over the sea bed looking for bombs. I hoped to dive with one of the Navy divers, but I couldn’t keep up. They took off like mini-subs, finning faster than I could possibly manage.

I finally caught up – wheezing deep breaths of recovery – when they stopped to examine a possible target: a 500lb bomb. It had been on the sea bed for a long time and any sign of paint had been replaced with marine life and rust. The diver worked around the bomb, checking the nose and tail looking for clues. Was it a live one or a practice round? I couldn’t tell. The fuse is normally at the rear of the bomb, but this one had been dropped at high speed onto solid rock, immersed in seawater and then had rolled around the sea bed for an unknown length of time.

The diver looked at me and gave a thumbs-up signal, which needed to go through the Navy-to-BSAC translator. In Navy-speak, a thumbs-up means ‘okay’, not the BSAC standard of ‘up’. It meant he was confident that this was a live one. He headed back to the surface to buoy the site and I started my own ascent. In total, the dive had taken no longer than 15 minutes. For these guys, diving is a means to an end, so there’s no time to enjoy the scenery.

Back on board the Tornado, the divers reported what they found, and a plan was formed for the bombs’ demolition. There are four basic parts to demolition charges: a detonator, a safety fuse, a detonation (‘det’) cord and the aforementioned bang. Safety fuses look just like the fuse Wile E Coyote used to light on the Acme rockets, but preparing demolition charges is a deadly serious business. The length of safety fuse is critical: a short fuse is burned and timed to provide a benchmark for calculating the length required for a five-minute timing.

With the charges prepped, we returned to the RIB. Finding the bomb was easy, and this time I made sure I had a head start before the diver arrived with the bang and started work. He secured the demolition pack to the bomb, taking care not to let the det cord form a loop. With the first bomb ready, he strapped a second pack to another bomb, and I returned to the surface. Once both bombs were ‘packed’ with the charges and both of us were safely back on the RIB, the Tornado crew broadcast a radio warning to all shipping and the range was declared clear.

The RIB motored a safe distance away and the countdown began. With a thump and plume of water, the charges detonated, but the bombs turned out to be practice rounds and the expected explosion of a 500lb bomb going off – sorry, initiating – didn’t happen.

The sea surrounding Garvie Island is open to whatever the Atlantic can throw at it. As we were diving on the east side of the island, we were shielded from the worst of the open ocean swell. However, there were targets on the west side, so the second day saw the Navy divers and I searching the rocky sea bed and finding a buried 1,000lb bomb. The diver set to work, strapping the charges on the casing of the bomb as the surge dragged us back and forth. With the nose and tail both covered by rock (and neither of us was about to start digging), he laid the pack on the casing and secured it with a pile of rocks, before heading towards the surface.

The dive was over in nine minutes. This one turned out to be another practice round, but the seagulls were grateful for the fish that floated to the surface soon after.

It had been a quiet year at Garvie, with the RAF running just 20 sorties – and of all the bombs dropped, only a few might have failed to initiate. The bombs we found were corroded and covered in marine life, and the chances are that they were all painted blue. The bomb disposal team may well have seen these bombs on previous visits and, because of their colour, not bothered to dispose of them. But with their paint gone, a practice round looks the same as a live one. On the last dive, I found two bombs – both missing their paint – but, thanks to a large dent where a demolition pack had been placed, it was obvious these bombs had been dealt with in the past.

In the bar later that evening, one of the more experienced Navy divers insisted I guess how long he had been diving. I had no idea. To prove just how much time he had spent underwater, he reached down the front of his trousers, delved into his underpants, grimaced, winced and, after much tugging, withdrew his now clenched fist. ‘Hold out your hand,’ he said. Unsure what to expect, I held out my upturned palm, and he dropped a limpet shell into my hand. ‘That’s been clinging to my plums,’ he said. ‘Proof of how long I’ve been diving.’

Diving with the Northern Diver Group at Garvie Island was a both a privilege and a pleasure. Civilian divers have been known to treat unexploded ammunition as souvenirs, but after witnessing the effects of high explosives first-hand, I will keep my distance. I wouldn’t want anything initiating near me!