Hand tools & Torsion box question
I've reviewed many inquiries on torsion boxes and found no info relating to this particular type of bench build. I built a general use workbench (assembly and outfeed) some time ago using a solid core door with a hardboard top. The frame for this bench was built torsion box style and it is very heavy and solid. I used a very old solid core door on top and used hardboard for a sacrificial top.
I am hoping to start a true hand tool woodworking bench very soon and want a 2' x 6' solid top made of SYP 3" thick. This will be my first hand tool bench and I want heavy and strong. I have a few vises (and will choose two) for this build and have a couple of ?? for those with relevant experience.
Q1. Is it necessary to access the underside of the top from the ends of the bench? Reason = I'd like to build torsion boxes (heavy duty ones) for the frame ends of this bench. My idea is to have the front and rear lower stretchers enter the framing of the torsion box sides ( as a tenon would enter a mortise). Having torsion box sides makes them a solid surface and restricts reaching under the bench top from the sides. The frame will be only about 3.5' long to allow for a face vise front left and a tail vise on the right end. Please visualize each leg made up of 3 layers of 2 by 6 material before the outer plywood layer is applied for extra strength and weight.
Since the vises are mounted outboard of the ends, they somewhat restricts reaching beneath the bench from the end anyway. Lower stretchers (doubled 2x6) along with the 3" thick top should provide strength in the lengthwise direction (think hand planning), but the ends would be easy and economical to make massive using dressed construction lumber and 3/4" plywood. Rather than build simple legs for the bench ends these torsion boxes would lower any reservations I have about putting a floor jack under an end, inserting a furniture dolly, then using the jack on the other end when and if I need to move the bench. Everything else in my shop is on casters, but I want the bench on the floor when in use.
Thanks for your knowledgeable input!