Ropes & Rigging

Last Friday 28th February 2015 in Antibes, experts Jean-Christophe Grimaldi & Gavin Hall gave the workshop “Ropes & Rigging” for Deck Crew. For the ones who were unfortunately not able to go to this workshop, we made a summary for you.

GREMCO is an Equipment & Technical service provider for Yachts since 1978. Providing Yacht care, Refit, Maintenance & service worldwide for: Super Yacht Management Companies, Shipyards & Refit Centres and directly to Yachts.

 

Understanding Ropes

Before we go further, let’s start with the basics!

A rope is a group of yarns that are twisted or braided together in order to combine them into a larger and stronger form called a rope. Furthermore, a rope can be constructed of different materials whereas each material will determinant of the ropes: strength, abrasion resistance, ease of use and price. For this reason it is important to have a basic understanding of the basic differences between the various rope materials available.

 

Different types of Materials

Polypropylene

  • Lightweight fibre that is also cheap.
  • Sailor’s point of view – it floats.
  • Unfortunately it is not very strong
  • Left outside in the sun it deteriorates quickly.
  • Melts at a low temperature
  • It’s easy to generate sufficient frictional heat to cause damage or failure.

 Nylon (polyamide)

  • One of the original synthetic fibres
  • Good shock absorbing properties,
  • Good Wear resistance and its imperviousness to UV light and chemicals
  • Loses strength when wet.
  • Melts at a low temperature
  • It’s easy to generate sufficient frictional heat to cause damage or failure

Polyester

  • If one were limited to just one fibre for all uses this would be it.
  • Strong,
  • Resistant to UV light and chemicals,
  • Kind on the hands and stretches just moderately when loaded.

Aramid (Kevlar, Twaron, Technora)

  • Despite their impressive properties, Aramids do not make ideal ropes.
  • Poor resistance to UV light – protective cover required
  • Low breaking strength when knotted
  • Internal friction in the rope core is the fibre’s downfall.
  • Repeated bending causes the strands of the core to rub together and this in turn causes friction damages. Unseen and undetected the core steadily gets weaker until one day, bang! Without any apparent explanation the rope breaks.
  • Unsurprisingly, Aramids are not any longer widely used in sailboat applications.

HMDPE High Molecular Density Polyethylene (Spectra and Dyneema)

  • HMDPE is an excellent material for ropes
  • light enough to float,
  • offers a very high degree of UV light and chemical resistance
  • Great flexibility
  • Very Strong
  • Can creep under constant load (plastic elongation)

Vectran (developed from an aramid)

  • Very strong fibre with minimal stretch and no propensity to creep.
  • Excellent abrasion resistance
  • Good fatigue strength so sudden failures such as those seen in Aramids should not be a problem.
  • Not good resistance to UV light so needs to be used inside a cover.
  • Very expensive

PBO – is an acronym for Poly Benzoxazole.

  • PBO has the highest strength and modulus of any synthetic fibre.
  • Double of Kevlar or Vectran.
  • Extremely low stretch
  • Very high melting point

 

Mooring

Now, let’s explain to you the different types of mooring.

Secure Line – Emergency anchoring and towing line   

secureline1  

  • 100% dyneema (20mm – BL 23000kg)
  • Light & floats
  • High resistance and abrasion

 

Storm Line – Mooring lines    

storm line                                  

  • Double braided polyester (20mm – BL 8,5kg)

 

Round Line – Mooring lines     

round line                                                 

  • 12 strand braid polyester (20mm – BL 5,4kg)

 

Square Line – Mooring lines

square line                                                     

  • 8 strand braid polyester (20mm – BL 4,2kg)

 

Sea King – Mooring Lines  

seaking                                        

  • 3 strand rope polyester (20mm – BL 6,7kg)

 

Square line (PP) – Mooring lines

square line (pp)                            

  • 8 strand braid Polypropylene (20mm – BL 3,7kg)

 

With its experience and knowledge, GREMCO can offer: Custom superyacht projects, Custom race yacht projects, Splicing, Mooring lines, Wire to rope splicing, Decorative leather and rope work and Traditional rope work.

For more information, please contact

Gavin Hall

GREMCO LOGO BLANCGremco SAS

1955 chemin De St-Bernard

06220 Vallauris –

France Cell: +33(0)6.11.42.03.49 Tel : +33(0)4.93.64.19.19 Fax : +33(0)4.93.64.80.18 Email : contact@gremco-sas.com www.gremco-sas.com