They gained the name `` Deltic '' from the prototype locomotive , British Railways DP1 `` DELTIC '' ( the running number DP1 was never carried ) , which in turn was named after its Napier Deltic power units .
They gained the name `` Deltic '' from the prototype locomotive , DP1 `` Deltic '' , which in turn was named for its Napier Deltic power units .