This permitted sixteen separate gangs of workers to be used during construction (one from each open end and two from the foot of each of the shafts).

[5] Four of these were subsequently filled in but three were retained for ventilation purposes and are still used as such today (with occasional ice accumulation problems[6]).

[7] The line from the south enters the tunnel on a rising 1% (1 in 100) gradient (the "Long Drag" beginning back at Settle Junction), but an initial summit is reached at the 1100 ft contour just under half a mile from the southern portal.

In April 1952 a passenger train derailed shortly after exiting the tunnel due to a broken brake rod on the locomotive tender fouling the points.

The use of rolling stock with Buckeye couplings and welded underframes was praised in preventing telescoping of the coaches and thus there were no deaths.