A British Airways Boeing 757, G-BIKG, callsign Shuttle 6N pushed back from stand A3 at London-Heathrow Airport at 10:13 UTC with no ATC slot time required. After starting engines, the aircraft was cleared by the ground movement controller to taxy via the outer taxiway for runway 27R. Three minutes earlier, a Gulf Air Airbus A340 (A4O-LB), pushed back from stand L3 to make good its approved departure time of 10:20 hrs and received the same clearance from the ground movement controller but, having a greater distance to taxi, was behind the Boeing 757 on its way to the holding area. Both aircraft entered the holding area via Block 32(O) where there was a queue of aircraft waiting to depart. At 10:20 the crew of Shuttle 6N were instructed to “HOLD FOR BLOCK 18”. The aircraft was taxied by the co-pilot from the holding area into the taxiway of Block 137 where it remained, stationary, until the accident. The A340 was behind several aircraft including an Aer Lingus Boeing 737 and an MD-11. At 10:25 the controller asked the MD-11 crew to “Pull over to the right hand side behind the Syrian Air” to which its pilot replied “You had us pull up behind the Aer Lingus so we can’t now”. Next the controller asked the crew of a Boeing 757 behind the A340 whether they could manoeuvre for a Block 18 departure but the crew replied that they were unable to do so. They were then instructed to “Pull over to the right hand side for a full length”. During the next five minutes an A320, a Boeing 727 and a Boeing 757 departed from the full length and a Boeing 737 departed from Block 17. Another Boeing 737 began its take-off run from the full length after the departure from Block 17. As it did so, the MD-11 followed by the A340 began to move forward. At 10:31 the left hand wingtip of the A340 struck the Boeing 757’s rudder and fin. The impact was felt in both aircraft. In the Boeing 757 two cabin crew standing by the aft galley received minor injuries when they lost their balance but no one on board the A340 was injured. After the collision the A340 commander taxied a few feet further forward to ensure that his wing tip was clear of the 757’s APU. Both aircraft then remained parked whilst the emergency services were summoned by ATC. A new taxiway had recently been opened to provide an additional access route from the holding area for runway 27R to the runway. Neither airport nor ATC management had studied the collision risks involved in using the new taxiway which was available to any aircraft regardless of size. The A340 pilot taxied by reference to the yellow taxiway centrelines. He had assumed that if he followed these lines, his aircraft would remain clear of any obstacles beside the taxiway. No ICAO Annex 13 Probable Cause statement was issued.