Redhill Tunnel South Portals (West SPC6 28 and East SPC6 28a)

The Redhill Tunnel South Portals consist of two entrances that form the southern access to Redhill Tunnel. The west portal was constructed between 1838 and 1840 for the Midland Counties Railway, designed by Charles Vignoles, while the east portal was built from 1892 to 1893 for the Midland Railway, likely designed by J. A. MacDonald.

The west portal is made of coursed quarry-faced sandstone with ashlar dressings. It is located at the end of a steep earth cutting and features a classical frame applied to a retaining wall. The semi-circular arch is constructed with ashlar voussoirs that return as quoins on the tunnel's soffit. The arch springs from a moulded impost band that extends across the abutments, forming the cornice of flanking pedestals. These pedestals support pilasters with plain, squared capitals, which have a picked dressing with tooled margins. Above, a square-profiled string course with similar dressings creates the architrave of an entablature. The frieze is made of three courses of quarry-faced stone, and the cornice features a cyma reversa moulding, topped by a low, recessed ashlar parapet.

The east portal features a horseshoe arch made of four courses of headers arranged in two steps, with an outer stone roll moulding. The innermost course of bricks is rounded as it returns to the soffit. This arch is flanked by two pairs of broad raked piers, with the outer piers marking the ends of the wing walls that rise with the cutting. The portal has a prominent ashlar stone roll moulding and a parapet made of a single course of ashlar stone.