JOHNSON – Dependability
The Johnson brand name stands for dependability. Whether it is a Johnson CUTLESS® Bearing, Johnson Stuffing
Box, Johnson Demountable Keel Cooler or the Johnson Commercial Dock Bumpers and Tow Knees presented in this
catalog, these products were designed to stand up to tough conditions presented by the commercial marine and
JOHNSON Commercial Dock Bumper
Johnson Commercial Dock Bumpers are produced using EPDM rubber (Ethylene-Propylene-Diene-Monomer).
EPDM was selected because it has exceptional resistance to weather aging and ozone – typically found in marine
applications. It also works in a wide range of conditions and ambient temperatures – also important in marine
applications. Use caution when purchasing commercial dock bumpers from other sources. Not all bumpers were
created equal. Not all bumpers are manufactured from virgin EPDM rubber.
Hole Drilling & Cutting Service
Duramax® Marine has over 40 years of experience in machining, cutting and drilling rubber parts for specialty
applications. Drilling mounting holes in the Johnson Commercial Dock Bumpers can be difficult without the right
tooling and equipment. You can save time and effort by having Duramax® Marine do the fabrication for you. The
cost is extra, but you will appreciate not having to do the fabrication yourself!
For installations where fender needs to be mounted on a curved surface, Duramax® Marine has the ability to
provide precurved dock bumper sections. When extruded rubber is cured straight and then held in a curved
position, there is stress in the part. This stress could be released upon impact causing the rubber piece to tear.
Precurved sections are cured with the curve in the part. The rubber is then relaxed in the curved state when you
mount it to the substructure. Upon impact, the precurved piece should not tear as readily.
In order to provide a quotation on precurved dock bumpers, please provide the following information to
1. Radius of the hull = R inches
2. **The angle of curvature = A degrees
3. The total length of fender against the hull from X to X
4. The thickness (height) of the fender section to be curved = T
5. The Johnson Commercial Dock Bumper type and dimensions
**If the angle of curvature cannot be determined, dimensions H and W can be substituted for A degrees.
Duramax® Marine recommends that the bending radius be no greater than 150% of the overall height of the cross
section. Note that precurving dock bumper will distort the shape of the bumper at and near the bend. Consult your
Duramax® Marine representative to determine if precurving is necessary for your installation.
JOHNSON Tow Knee Pusher Plates
For decades, Johnson has been one of the most trusted brands of tow knee pusher plates available. Like the
name, Johnson, our tow knees stand up to the test of time because Duramax® Marine specializes in rubber to
metal bonding and only uses the highest quality natural rubber.
Protect bows and docks from punishing marine use. Give vessels longer and better service life. Cut repair and
replacement downtime. And know that Duramax® Marine is the one you can trust. With one of the largest
inventories of tow knee pusher plates in the business, there is a good chance your Johnson tow knees can be
shipped by a Duramax® Marine stocking distributor or field warehouse from stock.