Building Better Top Beams

boat lift with stepped top beam holds large white boat in front of waterfront home

At IMM Quality Boat Lifts, our skilled engineers have developed a way of building better top beams for our boat lifts.

The original designs for boat lift top beams put the drive pipe and bearing blocks on top of the structure. This simple design was easy to manufacture with “off-the-shelf” parts. However, there was a risk that fingers and clothing could easily get caught in the exposed drive pipe and cable during lift operation. After a series of accidents, many municipalities have banned this design due to safety concerns.

IMM Quality boat lift that shows exposed drive pipe secured to top of the structure
This boat lift shows exposed drive pipe secured to top of the structure.

To address this safety problem, most manufacturers have now put the drive pipe inside the top beam structure. The top beams of typical boat lifts are made from C-channel and flat-wall bearing blocks. The bearing blocks are welded to the side of the C-channel and support the full weight of the boat.

Inferior c channel top beam design
An inferior C-channel top beam design

But what happens if there is a bad weld that breaks? There is no structure to support the weight, and your boat crashes into the water. The C-channel top beams are obviously not an ideal design, but they are the cheapest and easiest way to get the job done. But do you really want the safety of your boat relying upon this flawed design?

IMM Quality Boat Lift’s superior manufacturing capabilities allow our engineers the flexibility to make better designs because our machines can make any metal part. We are not limited to “off-the-shelf” parts. Instead, we make all of our parts in-house using our extensive array of CNC machines. Furthermore, we are willing to take our designs directly to the aluminum foundries and mills, where we have paid to have them make custom foundry dies. The aluminum mills use these dies to make custom aluminum extrusions that we machine into some of the parts for our boat lifts.

IMM Quality custom extrusion for the boat lift stepped wall bearing blocks
Featuring a custom extrusion for the “stepped” wall bearing blocks

IMM Quality Boat Lifts has a much better solution for boat lift top beams. Our engineers designed a “stepped” channel and paired it with a “stepped”-wall bearing block. The “stepped” walls improve boat lift top beams in several ways:

Diagram that shows positioning of stepped bearing block

First, the step increases the strength and rigidity of the channel. Think about holding a piece of paper by its edge. The paper does not stand out, but flops over because the thin paper is not rigid enough to support the weight. Now make a “Z” fold down the length of the paper to make a step. The paper will now easily stand out its full length when you hold it by the edge. These same physical principles apply to the top beam channel when we add the step to it, and we now have a channel with improved strength and rigidity.

Diagram that shows hand holding flat paper and stepped paper
Adding a step to a flat material increases its strength and rigidity.

Secondly, the steps greatly simplify the alignment of the bearing blocks within the top beam channel. By having the steps of the bearing block and top beam channel fit perfectly together like two pieces of a puzzle, we have eliminated the human error that can occur when the welder measures the vertical position of each bearing block. This feature makes sure that the bearing blocks are always perfectly aligned and that you won’t have to try to force your drive pipe through bearing blocks that are out of position.

Stepped channel top beam showing stepped wall bearing blocks welded into perfect alignment by imm quality boat lifts

Most important of all, the step provides physical support to the bearing block. The step in the channel creates a ledge upon which the shelf of the “stepped”-wall bearing block sits. Although it took more effort to design these patented custom extrusions, and although they cost more than an “off-the-shelf” solution, the effort is well worth it because nothing is more important than your safety. Even if a weld were to fail in the IMM-designed top beam, there is still aluminum structure to support the weight of your boat. Sometimes accidents happen, and when they do, you will be glad to have a boat lift engineered with redundant back-up safety features.

Exceptionally engineered and thoroughly tested, IMM Quality Boat Lifts are Built for a Lifetime.

IMM Quality boat lift holds large blue and white boat securely with stepped top beam