is depicted in relation to a mower deck 12 and a tractor 14 the mower deck carriage 10 includes channels 16 and 16 39 attached to the mower deck and roller assembly 18 the channels 16 and 16 39 receive rollers 50 and 50 39 not shown in fig1 which rollers 50 and 50 39 are supported on roller assembly 18 a guard rail 20 extends from the mower deck 12 the guard rail 20 supports guard rollers 22 referring to fig2 a plan cut away view of the mower deck 12 is depicted in the embodiment shown three mower blade pulleys 26 26 39 and 26 34 are supported on the mower deck 12 the mower blade pulleys 26 26 39 and 26 34 are each connected through axles 28 28 39 and 28 34 to mower blades 30 30 39 and 30 34 not shown in fig2 the mower blades 30 30 39 and 30 34 extending below the mower deck 12 a pulley belt 32 extends around the blade pulleys 26 26 39 and 26 34 a biasing pulley 34 is attached to the mower deck 12 the biasing pulley 34 includes spring means such that the biasing pulley 34 exerts a biasing force against the pulley belt 32 the biasing force maintains tension on pulley belt 32 as the biasing pulley 34 is a conventional commercially available pulley details of construction of the biasing pulley 34 are not depicted the blade pulleys 26 26 39 and 26 34 are each rotatable around their respective axles 28 28 39 and 28 34 by the pulley belt 32 the blade pulley 26 comprises a double pulley a.