The L4-1500XD-M and the S4-143 are Relcos' break into the new (rebuild) locomotive market. The CIC ordered 8 sets, which are all now in service. The 1500XD features a 12-645 EMD prime mover and AR10 alternator producing 1500-horsepower to provide power to the set. Every 1500XD-M is mated to a S4-143 slug.
An noteable feature of the locomotive is the the radiator section that features a raised fan above the long hood. This was a result of radiators placed inside the carbody to avoid having radiator wings protruding from the carbody.
Relco Plans to eventually expand its rebuild line, however as of 2014 no new Relco models have been made public.
Slug Mother model designation: L = Locomotive 4 = four-axles 1500 = 1,500 horsepower XD = Extreme Duty M = Mother
Slug model designation: S = Slug 4 = four axles 143 = ballasted weight in tons