Mast jack

A mast jack from Seldén ensures that you always retain the right rig tension for racing. It also lets you relieve the load on the rig and boat when you are in port. The mast jack system consists of a hydraulic cylinder located inside the mast. The cylinder piston moves down vertically through the heel of the mast to a steel plate in the boat’s T-base, thereby lifting the mast and increasing the tension. In order to make it easier to jack up the mast, the system includes a two-stage pump that switches to its lower gear as the pressure increases. When the mast reaches its upper position, shims are placed between the heel and the T-base. Release the pressure and remove the pump. Now, the rig is set in accordance with the predetermined requirements. So is the boom height, I-measurement and other rating measurements recorded by the measuring official. The pump is connected to the cylinder with stainless steel couplings, and can easily be disconnected and left ashore prior to racing. The hydraulic hose is then stored in a purpose-designed hose garage to keep it out of the way. The hose garage itself is fitted inside the mast. The T-base has the same pattern of holes as Seldén’s standard T-base, and its position can be adjusted in fore and aft direction to obtain the optimal mast rake.