The Whitley carried a maximum of 10 Paratroops, who sat on the floor, legs outstretched, opposite each other in a staggered line. Headroom was only around 4 feet in the narrow fuselage.
Exit was from the belly hatch, a 3 feet diameter hole, adapted from the redundant 'dustbin' ventral turret position, with the static lines hooked onto a cable running the length of the roof, each jumper shuffling into position to face forward for the exit from the aircraft.
Pushing off from the 'sill' of the hole too hard meant that the jumpers face hit the opposite side of the hole. Pushing off weakly invariably meant that the back-pack parachute caught on the lip of the hole, leading to a more violent contact with the opposite edge of the hole !
This was known as 'Ringing the bell'.
The diagram below shows the arrangement and jump order positions, with the photo giving some idea of the cramped conditions inside the Whitley. Note the Sten gun tucked beneath the parachute harness of the Sergeant in the foreground.
At the time of Operation Biting, the equipment leg bag had not yet been introduced, and each soldier wore his webbing personal equipment under the parachute harness, covered by a sleeveless jerkin (the famous Dennison smock was introduced later).
It was possible to carry a Sten gun, tucked into the harness across the chest, if the skeleton butt was removed - note that British Airborne Forces did not use a chest-mounted reserve parachute at this period, this not being introduced until the early 1950's.
All other weapons and equipment were carried in tubular metal containers, carried in the bomb bays, which were dropped in the middle of the stick (i.e., between parachutist No.5 and No.6) on their own parachutes.
This equipment would include Lee Enfield rifles, Bren guns, radios etc etc.
Make-up of each 'stick', or 'chalk', would depend on the operational requirements, but would generally consist of a 10 man Section, with the distribution of Ranks as appropriate.