Installing And Adjusting Watertight Door Dog Assemblies

Identify Before You Order

Watertight door handles are listed in more than one variant, and the difference is the shaft. The specification sheet lists handles with a square shaft and handles with a flat head shaft, each in two dimensional variants. Ordering the right dimension with the wrong shaft type gives you a part that cannot be fitted.

The reliable method is to photograph the existing assembly, including the shaft where it passes through the door, and send that with the enquiry rather than describing it.

Reading The Dimensions

The two figures given against each code are the dimensional pair that has to match the door. Measure the existing assembly on board and compare, rather than assuming a sister ship or a similar door uses the same variant. Doors get replaced individually over a vessel's life and a ship is often not internally consistent.

Fitting Sequence

• Confirm the replacement variant against the removed part before disturbing anything else on the door
• Clean the seating faces and check the door gasket while access is open — replacing a dog on a perished gasket solves nothing
• Fit the assembly without final tightening so the dog position can be checked against the wedge
• Close the door and check that the dog engages the wedge squarely across its face, not on a corner
• Adjust so the door seals with firm hand pressure; a dog that needs a bar is set wrong and will damage the gasket
• Operate the door several times cold and confirm the setting holds

Do Not Fix A Door Problem With The Dog

If a door needs excessive force to seal, the cause is usually the gasket, the frame or a distorted door — not the dog. Overtightening the dog to compensate crushes the gasket, and the door then leaks in the position where it was previously sound. Address the underlying problem and set the dog to normal hand pressure.

Related Hardware Worth Checking At The Same Time

While the door is being worked on, check the holder, the closer and the fasteners. Door closers are listed with a maximum door weight of 45 kg on the specification sheet; a closer under-specified for the door will fail again. Brass dog bolts and wing nuts are listed in metric coarse and Whitworth so an older door can be matched to its original standard.