On the H340, mast struts were used on the boats without in-mast furling. Apparently not needed on the boats with furling mains due to the smaller size sails and larger mast cross section.
This is true for the 410 also. From the 1998 owner's manual:
"The latest advancement to the B&R rig is the addition of mast struts. These struts stabilize the lower section of the mast, allowing compression loads to be spread, reducing the point loading at the mast base. They also create a strong point for the boom and spinnaker pole loadings. The struts function also allow us to use a smaller mast section reducing weight aloft to decrease the heeling and pitching moments, making for a more comfortable ride. Additionally, they provide a secure handhold when going forward.
The struts perform an important structural function, therefore never sail your boat without the struts properly fitted. If your 410 is equipped with the in-mast furling option, the mast is a larger section size and the struts are not utilized."
Daniel
svctime.blogspot.com
