The first four bolster wagons were supplied by the Metropolitan Carriage & Wagon Co., of Saltley in Birmingham as two sets of two in 1874.   The rendering below illustrates how the bolsters were operated in pairs to carry longer loads such as signal posts, telegraph poles and timber baulks.  L.3 and and .4 were scrapped in 1959 and the last pair, L.1 and L.2 survived in the goods yard at Douglas Station until 1974 when they were lost as part of the infamous Ballasalla Bonfire that same year.