Please select your home edition
Upffront 2020 Foredeck Club SW LEADERBOARD

Sailboat Load Data - Optimising Hardware and Rigging Design

by Phil Anniss 30 Jul 2020 09:00 PDT
Sailboat Load Data - Optimising Hardware and Rigging Design © Cyclops Marine

Find out just how far we still have to go in terms of understanding yacht mast and rigging loads, and why they are so important to the specification of sailing hardware and rigging systems.

Computer Aided Design

Yacht rigging and hardware design starts with some pretty fancy computer design tools, e.g. Finite Element Analysis (FEA) and Computational Fluid Dynamics (CFD). With all that computer power behind it, the expectation is that we must be approaching some super-optimised designs. In some areas we are, but in many others the colourful computer images hide an uncomfortable truth: these powerful models are only as good as the technical assumptions they are built on.

When you start to dig into these models, some of the core assumptions used are based on rule-of-thumb estimates, which have evolved over the last 30-50 years, rather than scientifically verified fact. Sometimes the computer model is tweaked until it delivers the expected outcome, which conforms to perceived wisdom of what should work!

There are two primary reasons why these assumptions have yet to be validated: a) a lack of available data on the complex dynamic loads at work in the sailing environment and b) the resources required to do the extensive, structured R&D.

Before everyone starts panicking, this is not to say that existing hardware and rigging is badly designed or not fit for purpose - it is. However, it has been designed based on years of trial and error rather than accurate computational design. The upside is that these powerful computer models may yet deliver significant future performance gains, if their core assumptions can be properly tested and validated.

And why is this search for increased performance relevant to everyday sailors?

At, "performance" doesn't necessarily mean coming first at the top mark, or maximum foiling speed, it means removing weight where it is not needed whilst making sure the fitting or rigging element is strong enough to do the job.

A fitting which is over-specified will be safe, strong and last a long time, but it adds additional weight which in turn puts unnecessary load into the system. On the other hand, a fitting that is underspecified will be nice and light but it will be working at a higher percentage of its designed break load, which means it will fatigue more quickly and possibly fail. So optimising our hardware and rigging design is about creating lighter and faster YET safer sailing - a win-win for all sailors.

So how do we optimise rigging and deck hardware?

If you take a look across the website you will notice that the most common product attribute is Safe Working Load (SWL), because this is THE primary specification criteria for most sailing hardware and rigging. But, do you know what the real load is in your jib sheet or main halyard? If you don't, then how do you make the right hardware choice?

Most of the time people use existing hardware as a guide, e.g. I need a block for a 10mm line, or something with an 8mm pin diameter. But every time you modify your boat, whether you get new, stiffer sails or add that dishwasher down below, you have an impact on the loads on your sailing systems. The only way we can improve hardware specification and optimisation is to have access to REAL load data.

Traditionally, load sensing technology has been expensive and difficult to install/maintain, with questionable data quality, due to calibration problems. Thankfully however, wireless technology, the proliferation of hand-held devices plus simple software interfaces have lead to some interesting innovation in the last few years.

Summary is all about performance hardware and rigging systems and, to that end, we are passionate about understanding rig loads. In future articles we will go into more detail on some of the great products currently available on our website in our new, dedicated Load Sensing category - Browse the full range of Load Sensors.

If you have any questions about your rig loads or hardware and rigging specification, please do not hesitate to contact us at

Related Articles

Ronstan SHOCK Blocks
Simple efficient low friction rings The name of the Ronstan SHOCK Block is derived from SHeaveless blOCK and reflects the growing trend for replacing ball bearing blocks, with "low friction rings", in a whole range of sailing system applications. Posted on 22 Jan
Ronstan Cam Cleats
Lighter, stronger and kinder to ropes Simple, reliable and extremely versatile, Cam Cleats are a staple on boats of all sizes, either as the primary rope holding solution on dinghies, or as part of a purchase system on larger boats and yachts. Posted on 15 Jan
Harken Small Boat Furler range
From 14ft dinghy to 30ft sportsboat there's a model for you Harken have a dedicated range of furlers for dinghies and keelboats up to 30ft (3mm, 5mm and 6mm diameter forestays). These are what would term "structural furlers", in that they are an integral part of the main forestay. Posted on 1 Jan
Harken Radial versus Performa Winches
Phil Anniss from talks about the differences Harken have an extensive range of winches which are split into two primary ranges: Radial and Performa. In this blog we help you understand the key differences between these ranges and guide you to the right choice for you and your boat's needs. Posted on 23 Dec 2020
New product launch - Karver V3 Furlers
A major redesign of the entire KF continuous line furler range Karver have just released details of a major redesign of their entire KF continuous line furler range. Almost 20 years of end user feedback and manufacturing experience have been brought together in this extensive upgrade. Posted on 18 Dec 2020
Improve your Race Starts
Velocitek V2 ProStart is the distillation of more than a decade of experience The new Velocitek V2 ProStart is the distillation of more than a decade of experience and customer feedback building stand-alone, GPS-based, distance-to-line starting aids. It's all about time and distance. Posted on 10 Dec 2020
How Long is my Furling Line?
Guide to estimating when you can't measure It's a simple question but if you are buying a new furler or need to organise a replacement furling line and do not have access to measure it....... how long should it be!? Posted on 3 Dec 2020
Continuous versus Discontinuous Standing Rigging
Looking at the differences, and pros/cons of both types Regardless of material choice (wire, rod or composite), there are two main types of lateral rigging configurations, referred to as Discontinuous or Continuous rigging. Posted on 26 Nov 2020
Celebrating curves with the LOOP Flexi Stick-on
These padeyes can stick to a curved surface, and take a lot of weight You would probably agree that there are very few flat surfaces on a sailing yacht, whereas most hardware bases are flat. Using modern materials and construction methods, the innovative LOOP Flexi Stick-on padeye offers some interesting possibilities. Posted on 19 Nov 2020
Straight Talking
Mast and standing rigging terminology from is all about performance sailing hardware and rigging systems. The heart, and driving force, of any sailing yacht is its mast and standing rigging which support the sails. In this article we outline the key terminology. Posted on 12 Nov 2020
Upffront 2020 Foredeck Club SW FOOTER