Fertiliser, batteries, blocks of wood, saw blades, copper wire, a car inner tube, perhaps some foam packaging and ball bearings — it takes little more than the contents of the average garden shed to gather the basic ingredients of a Taleban bomb.

Most of the improvised explosive devices (IEDs) that the Taleban’s bombmakers produce use home-made explosives and are simple in their design and construction, British bomb disposal experts say.

While some roadside bombs use command wires or remote control detonators, most simply employ a pressure-plate detonation mechanism to complete an electrical circuit under the weight of a passing vehicle.

But in terms of the guile with which the Taleban place the devices and the sheer scale of their bombing campaign, they are better than the IRA, according to one bomb disposal expert. And the devices they use are becoming larger and more powerful.

“I hate them [the bombmakers], but I respect their skills,” admitted Sergeant Sean Powell, a bomb disposal specialist with a unit of the Royal Engineers known as Team Rainbow. About 80 per cent of the IEDs planted by the Taleban are being detected and defused by Explosive Ordnance Demolition teams.

The British bomb disposal squads currently deal with an average of 450 devices on a six-month tour of duty. It is slow and tedious work and often ends with the disposal experts crawling towards live bombs armed with little more than a basic tool kit and their courage.

Last year Warrant Officer Gary O’Donnell was killed while attempting to defuse a device. He had already won the George Medal for bravery and was posthumously given the award a second time.

The crews spoke about the particular problems they had faced with multiple devices planted around Sangin. It was just such a series of devices that caught the men from 2 Rifles on Friday.

The bombers had buried several devices to anticipate the route of a patrol, then the arrival of medics to deal with the initial blast, then the helicopter evacuation that would inevitably follow if the first devices had proved effective.

It marks a new level of sophistication in the Taleban’s development — a process remarkably similar to the insurgency in Iraq, where Western forces were ultimately subject to few direct attacks, but instead faced a proliferation of roadside and suicide bombings.

As in Iraq, Western forces are locked in an arms race with the bombers in Afghanistan. Both sides are constantly creating new ways to plant, construct and detonate or anticipate, detect and deactivate bombs. Many of the Western defences against the bombs cannot be described for reasons of operational security enforced by the Ministry of Defence.

Two years ago one British bomb disposal officer said: “The Taleban have a few people with a lot of knowledge and a lot with a bit of knowledge.” At that stage the insurgents were, for the most part, using old munitions and mines left from the Russian period to produce IEDs.

However, this year the Taleban has perfected the manufacture of homemade explosives. That suggests that they have largely run out of more complex ordinance and don’t have the resupply lines to replace it.

But what the new devices lack in technology and shrapnel, they make up for in raw blast energy. Often they are buried in pressure cookers, or in plastic buckets.

Ordinance professionals believe that even if complex explosives are not reaching the Taleban from external sources, expertise in bombmaking and planting is.

The bomb disposal crews may find the overwhelming majority of the devices, but the old maxim applies — British forces have to be lucky all the time, but the Taleban just need to be lucky once.

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