Rigging, Running, Main Sheet Blocks and Main Sheet Replacement

The new main sheet blocks and main sheet
On a sailboat, the main sheet is the line that controls the mainsail. It is roven through a series of blocks between the traveler and the bales of the boom. On the Ericson 25, the main sheet serves this normal purpose, but also serves another one - it is the primary means by which one steps the mast. In this instance, it is led forward to the mast winch, where an individual uses the mechanical advantage of the main sheet blocks and the winch itself to raise the mast from a horizontal to a vertical position. For both of these reasons, the main sheet and the main sheet blocks on the Ericson 25 must be in good condition and working order. In this article I discuss my replacement of the main sheet and the main sheet blocks. This project was part of my greater project of refurbishing the spars and rigging of Oystercatcher, my Ericson 25.
If you've read my article, "Spars, Boom, Hardware, Removal and Reinstallation," then you'll know that I removed, inspected, and reinstalled all the hardware on the boom of Oystercatcher.
During the inspection of the bales, I noticed that the plastic main sheet blocks, after some 40 years, were showing their age.
The forward block possessed at least one crack. This didn't look good.
The center block was in better condition. The main sheet itself, however, looked horrible.
The center block from a different angle.
The cheeks of the fiddle block were brittle. The side of one of the cheeks was chipped. When I pressed on the other side of the cheek with my fingers, the plastic cheek snapped.
The aft block possessed a crack not unlike the forward block. All of this made me worried, especially since I planned to step the mast with this main sheet and these main sheet blocks.
After some thought, I decided that all of this had to go. Therefore, I grabbed my wire cutters and snipped off the cotter rings that held the blocks to the bales.
These cotter rings were rusty and brittle. If I had decided to keep these blocks, then I would have, at a minimum, replaced the rings and clevis pins.
Having researched the subject of lines and rigging quite a bit, I decided to purchase Samson brand rope from Defender Industries in Connecticut. For the main sheet, I opted for Samson Trophy Braid. This is a good, high-tech, low-stretch line, yet one that won't break the bank. I also liked the fact that the Trophy Braid has, as Defender says, a "soft fuzzy cover that's easy to hold in wet or dry conditions." Trophy Braid comes in a variety of colors. I selected red. This would make the main sheet highly visible, and it would provide a nice accent to the color theme of the boat - white, black, and brown. Like the bird after whom this boat, Oystercatcher, was named, this boat would have a little red thrown into the mix. At the same time that I ordered this main sheet, I ordered the halyards for the main sail and genoa. I discuss these in a separate article.
I ordered 35 feet of 7/16 inch Trophy Braid. I decided to order 35 feet instead of 30, which was the length of the original sheet, just to give myself some extra. As it turned out, I could have used 40 feet. 30 feet is probably just right for the main sheet itself. When you use the main sheet for stepping the mast, however, 40 is better. I explain this more fully in my article, "Spars, Mast Stepping." I considered ordering 3/8 inch Trophy Braid, but I liked the feel of 7/16 in my hand much better. Therefore, I ordered 7/16 inch. The Trophy Braid in this diameter had an average tensile strength of 4,000 pounds.
My choice of 7/16 line for the main sheet dictated the size of the blocks that I selected to replace the old ones. After conducting some research, I settled on Garhauer Marine in California as the source for the new blocks. I had earlier purchased a stainless steel anchor roller from Garhauer and been impressed with the quality and the price. These blocks were high quality, and they were more affordable than anything sold by the big names such as Schaefer and Harken. All of these blocks that I purchased from Garhauer were of the US class, which in Garhauer-speak means "Unibody Standard" stainless steel. By "unibody" Garhauer means that the cheeks for the blocks are of one solid piece of stainless steel. This, they say, "distributes the total load more evenly across a larger surface." All of these blocks from Garhauer were also of the 30 series, which means that they have a working load of 2,400 pounds and a maximum line size of 1/2 inch. The next size smaller Unibody Standard stainless steel block was the 25 series with a working load of 1,150 pounds. The maximum line size for this block was 3/8 inch. Therefore, I could not use 7/16 inch line in this block. This line would have been too large.
The specific blocks that I ordered were as follows: three, single blocks with adjustable shackles (30-13US); one, single block with becket and adjustable shackle (30-14US); and one, fiddle block with becket, cam cleat, and adjustable shackle (30-06US). As you can see in the picture below, the fiddle block was comparable in size to the original fiddle block. The others, however, were considerably larger. If I had to do it all over again, I would probably opt for the Series 25 blocks, because the Series 30 blocks are almost too large for the space between the boom and the traveler. I must say, however, that it sure is nice having that 7/16 line in my hand, and it takes almost no effort to sheet in the main, even in a blow. I'm talking casual, one-handing sheeting.
I began by joining the becket on the fiddle block to the adjustable shackle on the middle block.
Then I laid out all the new blocks beside the old ones to remind myself of how they should be roven.
The becket on the middle block was used to terminate the main sheet. Here there was a bowline.
Therefore, to the becket of the new middle block I tied the same knot.
After I got a good sense of things in my mind, I carried the blocks and the main sheet outside and joined everything to the boom. Here's how it looked when I was finished. I thought it looked quite nice.
I thought it looked even nicer seeing it in action out in Charleston Harbor.
This ends this posting on how I replaced the main sheet blocks and the main sheet on Oystercatcher, my Ericson 25.

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