Rimutaka Incline Rimutaka Incline The Rimutaka Incline was a , gauge railway line on an average grade of 1-in-15 using the Fell system between Summit and Cross Creek stations on the original Wairarapa Line in the Wairarapa district of New Zealand. The term "Rimutaka Incline" is sometimes used incorrectly to refer to other parts or all of the closed and deviated section of the Wairarapa Line between Upper Hutt and Speedy’s Crossing, near Featherston. The incline formation is now part of the Remutaka Rail Trail. The construction of a railway from Wellington to Masterton was authorised in the Railways Act passed on
Rimutaka Tunnel cutting for the new formation completed and the remainder of the track laid. On Thursday, 3 November, the new line was opened and two special trains travelled from Wellington to Speedy’s Crossing to the inauguration ceremony. The deviation's ruling grade is 1 in 70, compensated for curvature. The tightest curve is 400 metres (20 chain) radius. The tunnel rises at 1 in 400 from the western portal to the highest point on the deviation, roughly halfway through the tunnel, and then descends to the eastern portal at 1 in 180. It has an internal height of 5.18 metres (17 ft)