the River Orne. A few minutes later, between 23:00 and 23:20, six Armstrong Whitworth Albemarle transports took off carrying pathfinders of the 22nd Independent Parachute Company, who were to mark the three drop-zones to be used by the airborne troops of the division. Another sixteen Albemarles followed the transports carrying the pathfinders, these transported elements of the 9th Parachute Battalion, 1st Canadian Parachute Battalion, and 3rd Parachute Brigade Headquarters. Thirty minutes later, the remainder of the transports carrying the division began to take off. This wave was divided into three groups. The first consisted of 239 Douglas Dakota and Short Stirling transports as well as seventeen Horsa gliders, carrying the bulk of the 3rd and 5th Parachute Brigades and their heavy equipment. These forces were due to land in their respective drop-zones at 00:50. The second group was destined to land at 03:20, and consisted of sixty-five Horsa and four Hamilcar gliders transporting the divisional headquarters and an anti-tank battery. The final group was formed of three Horsa gliders carrying sappers and men from the 9th Parachute Battalion, who were to land atop Merville Battery at 04:30. Capture of the Caen canal and Orne river bridges The first unit of the 6th Airborne Division to land in Normandy, was Howard's coup-de-main force. The coup-de-main force landed in six gliders, over a five-minute period (00:15–00:20); three landing near the Caen canal bridge and two near the Orne River bridge and the third destined for the Orne River bridge some seven miles away due to a navigational error. Once on the ground, the troops emerged and assaulted the German positions. At the Caen canal bridge, troops assaulted German trench positions, attacked sentries, and threw grenades into a concrete bunker believed to hold the triggering equipment for the bridge demolition charges. At the Orne River bridge, a machine-gun nest was suppressed with mortar fire but no other defenders were found, and the two platoons captured the bridge before radioing Howard and informing him of their success. Both bridges had been secured within fifteen minutes, at the cost of only a small number of casualties. It was also discovered that the bridges had not been rigged with explosives as believed. While the force waited for the rest of the division to land, and for the 7th Parachute Battalion to arrive to reinforce their position, they had to repel several spontaneous attempts by the Germans