The tunnel is located west of the site of Pudsey Greenside railway station and of the bridge leading Carlisle Road across the former line, and east of a bridge of Smalewell Quarry track, beneath the Fox and Grapes public house.[3][4] It is 616 yd (563 m) long,[1] according to some sources 618 yd (565 m),[2][5] and led a double-tracked railway beneath a hill on the western side of Pudsey town. The tunnel has not been built in a straight line, but with a slight S-shaped curvature that nevertheless allows to keep at least one entrance in sight at any point of its route. A ventilation shaft had been built about 240 ft (73 m) from its western portal. Its opening was located near today's junction of Westroyd, Windmill Hill, and Smalewell Road, beneath an access road to some garages, but is now capped off.[5]
The eastern portal is located below steep retaining walls on the south side of the approach cutting. Since closure of the line, it has been partly blocked by tipped spoil. The lining consists of masonry side walls with a height of about 7 ft (2.1 m), the roof arch has been constructed from engineering brick. Throughout the tunnel, amply-sized refuges in brick have been provided at regular intervals. The western portal is built from stone with buttresses and wing walls to each side.[5]
