The first double shear hanger was the HUS, which appeared on the cover of the 1984 connector catalog. (Sorry that the image is a little dark. Thankfully, our photography and art design have improved over the last several decades.)
We’ve discussed two types of bolted holdowns — the original welded HDs and their automated replacements, the HDAs. Just one year before the HDAs were introduced in 1988, our first nailed tension ties showed up.
Mudsills commonly attach to the foundation using cast-in-place anchor bolts. It can be labor intensive to lay out the anchor bolts, drill holes in the mudsill at the right location, and then bolt everything together. A very popular solution for anchoring mudsills is our MASA mudsill, launched in 2009.
On day three, I talked about our first holdowns, the HD2 thru HD15, which were welded holdowns that use bolts. A major innovation in bolted-holdown manufacturing was the introduction of our HD2A through HD20A holdowns in 1988. The “A” stood for automated because these products were manufactured on a die that stamps out finished parts, eliminating welding and significantly decreasing costs.
We manufactured the original U hangers with 16-gauge galvanized steel. In 1959, we created the heavy-duty HU hangers from 1/8″-thick steel angles and a gray primer coat. The HU hangers were available with and without top flanges.
Holdowns first appeared in the 1966 connector catalog — all two of them. The HD24 was an embedded strap that used either nails or bolts, and the HD2 used bolts to the post and an anchor bolt to the concrete. This first sighting of holdowns was missing a list of allowable loads.
I recently wrote about the H1A hurricane tie in this post, which discussed the original H1 hurricane tie first appearing in 1972, and the subsequent changes over the years that led to our current H1A. The original H1 along with the H2 and the H3 were the first products to appear under the label “hurricane ties” in our catalog.
We have our new Simpson Strong-Tie Wood Construction Connectors catalog coming out in January. In anticipation of this, I wanted to do a series of short, daily posts discussing the history of Simpson Strong-Tie products, catalogs, and random trivia through the years. In the winter holiday spirit, we’ll do this in “Twelve Days of Christmas” style.
Simpson Strong-Tie’s Greg Bundy, Senior Branch Engineer in Columbus, Ohio, recently led a training webinar on mass timber advancements. The workshop covered topics like the NHERI TallWood Project and a new guide for cross-laminated timber diaphragm design. The hands-on session featured installation of innovative products for structural engineers.
In response to the increasing demand for mass timber construction, Simpson Strong-Tie has created mass timber solutions for these builds. These product addition, include our Heavy Seated Knife Plate (HSKP), ACBH concealed beam hanger, and CBH concealed beam hanger. Gain insights into the design, testing, and efficiency of the HSKP in achieving high loads with fewer fasteners. The blog underscores the structural mechanics and the ongoing process of pushing connector limits in mass timber construction.