Webbing Jackstays

Webbing Jackstays lay along the deck for you to clip onto with your harness safety line, also known as a safety tether.

Jimmy Green Webbing Jackstays are made to measure, in house, by the Jimmy Green Sewing Team, on a modern, automatic profile, heavy duty Ultra-Sew machine using a tested and proven, jig-controlled stitch pattern so you can rely on their consistency, strength, and durability.

Jimmy Green webbing jackstays are produced in high tenacity, UV and abrasion resilient, UK manufacture, 100% polyester webbing.

MBL 2000kg, available in Blue, Red, Yellow, and Black MBL 3000kg, available in White

The 25mm webbing will fit comfortably onto the pin of our Extra Wide Stainless Steel Shackles.

Webbing Jackstays - Custom Build Instructions

The reasoning behind Webbing for Jackstays

Webbing lies flat, so it is less obtrusive and kinder to your deck than wire.

Wire and rope may tend to move or roll under your feet.

Wire can be PVC coated to prevent damage to your deck, but this increases the diameter and exacerbates the 'roll' problem.

Rope will need to be either more substantial in diameter or relatively 'high tech' to achieve the same breaking strain.

High Tenacity polyester webbing has excellent abrasion and UV resistance.

Jackstay Webbing strength compares favourably with wire.

Webbing Jackstay Fitting Considerations

1. Safe Attachment - It is critical to clip onto the jackstay line while you are in the cockpit and still venture as far forward (and aft) as possible without having to detach yourself. This means that the jackstay line needs to 'overlap' the cockpit domain (it should at least run outside the coaming so you can reach it from inside the cockpit). It also needs to negotiate a path around or over the natural obstacles such as hatches, lower shrouds, grab rails, cleats, windlasses, bollards, etc. so that the person clipped on to the jackstay line has a clear path to the forestay/pulpit (or pushpit)
2. Man Overboard Prevention - the path forward should be as near the centre line as practicable, e.g. inside shrouds, over but commonly around the curve of the coachroof. Clipping on to a jackstay that is too near the guardrail may result in dangling in the water, especially if you are outside the leeward rail with the yacht heeled going upwind.

N.B. The MAIB SAFETY BULLETIN 1/2018 - PDF has highlighted the importance of routing any jackstay or lifeline in such a way as to minimise the chances of a hook getting caught underneath any deck fitting and mooring cleats in particular.

"SAFETY LESSON To prevent the strength of a safety harness tether from becoming compromised in-service due to lateral loading on the tether hook, the method used to anchor the end of the tether to the vessel should be arranged to ensure that the tether hook cannot become entangled with deck fittings or other equipment."

Measuring your Jackstays

All deck jackstays should be fitted so that there is a degree of lift in the centre of the line before any significant load is applied.

The height of the lift should be proportional to the overall length of the jackstay and make allowance for the stretch of the jackstay.

Webbing Jackstays should be fitted taut to prevent too much slack when applying a body weight load.

The Jimmy Green Sewing Team Finished Length Process for Webbing

Webbing has a degree of stretch even at low loads.

1. Stitch one end
2. Connect the stitched end to a shackle with a large, robust measuring tape attached, and lay the webbing out taut but not stretched along the floor/trough
3. Identify and mark the turning point for the sewn loop at the other end of the webbing
4. Complete the second stitched loop
5. Check the finished length against your order

N.B. The website will accept a length to 3 decimal points. However, this is not practicable for webbing. The Jimmy Green Sewing Team can produce jackstay lengths to the nearest centimetre, i.e. to two decimal points. However, because webbing has a degree of stretch at a relatively low load, Jimmy Green Marine can only accept responsibility for the final measurement as follows: < 5 metres accuracy overall to the nearest 25mm. > 5 metres accuracy overall to plus or minus 0.5%, e.g. 6m metres = 30mm, 8 metres = 40mm, 10 metres = 50mm

Selecting your fixing points

Jackstay strong points should be selected according to the principles listed above. If there are no suitable fixing points in the correct position, you may need to fit our Jackstay U Bolts.

Sewn End Options

Standard Sewn Loops for attaching to shackles - the shackle is wide enough for the webbing to fit on the shackle pin.

Jimmy Green Extra Wide Shackles

Standard Sewn Loops with extra wide shackle included.

Twisted Sewn Loops - These are for passing the other end around, e.g. a stanchion base and back through the twisted loop. This creates a 'cow hitch' finish which means the loop will sit comfortably on the deck fitting. You will need to estimate the length required to go around the deck fitting</>

Sewn Lanyard Loops - These are longer loops to allow for multiple reeving of the lanyard.

Lanyard on Sewn Loops - These are longer loops with 2 metre spliced lanyard included Loop with Makefast Adjuster - 30cm Loop (laid out flat) created by threading the webbing onto the locking part of a Makefast 3541 Jackstay Anchor and back through the Gate Adjuster with a 20cm heat sealed tail 

Sewn Loops with stainless steel ring - lanyards can be spliced onto the ring.

Sewn Loops with stainless steel triangle - lanyards can be spliced onto the triangle.

Adjustment

Extra wide shackles make a strong and secure fastening at one end, but achieving the right degree of tension with shackles at both ends may be challenging.

Lanyards at one end make the measuring, tensioning, and fitting more straightforward.

Subtract approximately 200mm - 300mm from the overall length to create the gap for the lanyard.

Lanyards are produced from 5mm LIROS Pre-stretched Polyester: manufacturer break load = 600daN = approximately 610kg. The lanyard will require a minimum of 4 turns to ensure a comparable break load to the stitched webbing and the spliced rope.

Webbing Jackstay Guidance