sentences:  A horse drawn narrowboat is brought into service by "The Friends of Cromford Canal" occasionally on the only navigable section of the Cromford Canal near to the Derbyshire village of Cromford itself.The tunnel has been extended twice since it was originally built.The Midland Railway's Ripley to Heanor branch was built across the front of the Western portal with a new section of tunnel passing underneath bringing the total length at this time to 3063 yards (2801m).