 On 13 April 1986 , a British Rail Class 37 37427 was named " Bont Y Bermo " to celebrate the ( short @-@ lived ) re @-@ introduction of locomotive @-@ hauled trains following repairs in 1985 – 1986 . Following major repairs the weight restriction was relaxed in 2005 , and locomotive @-@ hauled trains have again been allowed to cross . 
