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BACKSTAY

The standard boat in this case comes with a good backstay arrangement that is led to each side where it can be adjusted by either the mainsheet trimmer or the helmsman. The system has a series of 2:1 'cascades' which double the power of the system at each one. It starts off with a HAR737 Stainless Runner block. This is sized to suit the breaking load of the standing backstay. The second block is a HAR6057 75mm ESP block, then dropping down to a HAR2660 75mm Carbo block. This gives an 8:1 (2*2*2) cascade before the final 6:1 purchase.

The final purchase uses 29mm Carbo Blocks with a HAR344 29C Triple at the top and four HAR340 29C Single blocks at the base, neatly organised on the chainplate. This gives a total purchase of 48:1, meaning this is an effective and easy to use tuning tool. The final controls are lead to each side through four HAR350 29C Cheek blocks, one at each corner of the transom, and one at each side of the wheel. The lead then runs up the cockpit side to HAR150 Cam-Matic cleats with HAR375 Extreme Angle Fairleads to allow adjustment from any angle. This allow you to repeat settings, calibrate the backstay by marking at regular intervals along the first cascade line and referencing this against the position of the triple block.

Upper backstay cascades
to final purchase.

Neat detailing on the
backstay chainplate. Note the
elastic to hold the blocks
upright when lines are loose.

VANG

Most standard production cruiser/racers do not have sufficient purchase in the vang to make it an effective, easily adjustable tuning control. This of the times when you are sailing a little 'pressed' downwind in some breeze and need to ease the vang in a puff. It is locked solid in the cleat, you cannot release it easily until it is too late and you wipe out. It is not the fault of the cleat, it is simply a symptom of insufficient purchase in the vang.

On the 34.7, the vang system is composed of a number of 2:1 cascades leading to a 4:1 purchase and then a single tail to a HAR240 swivel jammer in the centre of the coachroof. This allows any of the crew to get to the vang tail to easily adjust it.

Three vang cascades lead to
final 4:1 purchase.

The top block is obviously the most loaded block in the system and is a HAR6057 75mm ESP Teardrop, leading to a HAR6065 57mm ESP Teardrop and then a HAR2600 57 Carbo single. This gives an 8:1 purchase which is then attached to a 4:1 final purchase using 40C Fiddle blocks, HAR2655 & HAR2656. This give a 32:1 total purchase giving plenty of power to use this as an effective tuning tool and, probably more importantly, keeps the load on the cleat low for easy uncleating.

Three vang cascades lead to final 4:1 purchase.