Saturday, April 9, 2011

Cabin top handrails, postscript

I meant to include this photo in the last post on cabin top handrails.
If bronze machine bolts are used to install the handrails, and you see discoloration like this at the handrail attachment point, the bolt has corroded badly and the handrail is unsafe for use.

Cabin top handrails

Cabin top handrails are a classic feature on many sailboats, including Talofa Lee. The looped rails along the cabin top allow some security when moving along the deck and onto the cabin top.  Made of teak, and through bolted through the cabin top with bronze machine bolts, they can be pretty, strong, and useful.

However, as I found out on Tensie Mae, the rails are prone to leak at many of the bolt locations where the rail loop meets the cabin top.  When leakage occurs, the bronze bolts corrode, wasting the bolt where it can't be inspected without removing the rail.  On both Tensie Mae and Talofa Lee, many of the bolts had completely wasted away, or were so thin that their strength was minimal. Reliance on these handrails under these conditions could have resulted in a fall or a man overboard.

I decided to forego the classic look of the rails on Talofa Lee. Perhaps with additional attention, the teak hand rails would provide good service for a longer time, but I decided that instead of rails, I would use lines along the cabin top. Line is easily inspected, easily replaced, and economical compared with teak...and it doesn't have to be sanded and sealed. I used five eighths inch double braided dacron because of its high strength and because its diameter makes it a comfortable hand hold.

I raised the line off the cabin top using inch and three eighths mahogany "risers." I through bolted five sixteenth inch stainless steel eyebolts with nylon insert nuts through the cabin top to retain the line. I backed the bolts with stainless steel fender washers. I used four bolts and risers on each side, and eye splices in the line to affix the line to the end bolts.

I plugged the unused handrail bolt holes with bedded machine bolts. I will likely use these holes as mounting points for internal hand holds in the main cabin.
I think this installation is strong enough that the lines can be used as jack lines, allowing me to avoid putting jack lines along the side decks for heavy weather. These lines, plus strong points in the cockpit and on the foredeck, will provide full time security in fair weather or foul.

Stanchion and Lifeline Replacement

I am still waiting for the new fuel tank, so I have been working on other things that I have to complete to get Talofa Lee back in the water.

Stanchions are a priority for me, because I wanted to make a couple of significant changes from the stock installation and because of the changes, I couldn't re-install the ceiling strips on the bulkheads until new stanchions were in.  I wanted the strips installed so I could move ahead with some interior tasks.

The biggest change I had in mind were moving the stanchion mounting outboard to the gunwale to make passage along the side deck a little less intimidating. Norsea 27 side decks are narrow, and stanchions are typically mounted on the side decks just inboard of the toe rail.  Through bolted through the deck with quarter-twenty machine bolts, the installation is rigid and secure under normal conditions.

However, on Talofa Lee, the stanchions had a few significant problems.  First, on the port side the after deck was apparently drilled for stanchion installation before checking the cabinetry below decks, and the deck had to be re-drilled a bit forward to allow machine bolt installation.
Also, all the stanchions have been severely stressed at some point and their baseplates are bent.  The deck near the stanchions has some crazing.  New gelcoat has been laid under the stanchion bases.
When I pulled the stanchions, I found the core in the side deck to be locally damaged at the stanchion attachment points. Moving the stanchions to the gunwale means I can defer repairing the deck core until later.  After removing the stanchions, the mounting holes open have been open for six months with the boat under the cover of the barn and that has allowed the core to dry.  I sealed the mounting locations from weather by using the stanchion backing plates above, and fender washers below decks.
I stole the idea to mount the stanchions on the gunwale from Greg Delezynski on Norsea 27 Guenevere, which has beautiful bronze mounts and stanchions on her gunwales.  I know there is a school of thought that the stanchions shouldn't be outboard because you can catch them on a piling or dock when mooring or leaving a dock, and I considered the risk and decided to take it.  Also, the outboard stanchions may minimally foul the routing of jib sheets for smaller jibs when close to the wind, but I can use fairleads and blocks and get a fair lead for the sheets.

Because I wanted to do some things in addition to moving the stanchions outboard, I didn't use metal tubing for the stanchions, but used wood backed by stainless steel plate.  The stanchion is two by two mahogany backed by 0.188 inch stainless. The upper section of the stanchion is two by one and a quarter inch. The arrangement was through bolted through the hull with five sixteenths inch stainless steel bolts backed with heavy fender washers inboard.

The lifelines are half inch double braided polyester, routed through eye straps through bolted to the stanchions by quarter-twenty machine bolts.  I chose double braided line rather than wire because it is easy to work with, easy to inspect, easier to grip, and easy to replace.
I intend to paint the top two inches of the stanchions, above the upper lifeline, with reflective paint so it's easier to see them when moving along the side deck at night, and also easier to identify the boat at night among others when anchored in a group of boats.

I also installed an additional stanchion along each side deck.
The extra stanchion gives the lifelines added support.  They also allowed me to bolt an oaken bulwark in the area most needed...where the first step out of the cockpit is taken.  They allowed me to add a couple of hawse pipes and a cleat on each side to run breast lines from midships.  And the oaken bulwark significantly improved the load bearing capability of the stanchions by distributing load on one stanchion to the other.

I have pulled and hauled and pushed and shoved on the stanchions and the bulwark cleat, and they seem to be very strong and rigid.  I don't intend to shock load them to test them.

These wooden stanchions will likely be very useful for mounting solar panels.

This project was a bit more complicated than I thought at first, and I gotta give my cousin Byron kudos for helping me do this.  Getting the correct angles on the stanchion faces at the gunwales, and aligning the port and starboard stanchions to the same angles was a bit tedious, and he showed himself to have a good eye for this work.