Please select your home edition
upffront 2018 Generic 728x90

Karver KJ Jammer

by Prinal Shah 18 Sep 2019 01:00 PDT
Karver KJ jammers in use © Karver

French hardware manufacturer, Karver has been active in the French offshore sailing scene (IMOCA and offshore multihull) since its inception in 2004. Their reputation is based on developing a range of innovative products that combine ergonomics, efficiency and lightweight. One of these is the: Karver KJ Jammer.

What is a Jammer?

For a full definition of a jammer versus a clutch, see our previous blog here. Interestingly, despite its name, the Karver KJ jammer could be argued to span the two definitions, being releasable under (low) load together with the reliability of a high load jammer.

The Karver KJ Jammer comes in four sizes KJ10, KJ15, KJ25 and KJ50 with Safe Working Loads (SWL) ranging from 1 - 5 tonnes and for use with ropes from 5 to 20mm.

Additional Features / Benefits

Lightweight - innovative design and the use of ultramodern materials gives the unit a very high strength to weight ration

Full Remote operation - Both the locking and unlocking mechanisms are in-line with the load on the rope and can be operated remotely by trip lines. This has some significant advantages and allow the position of the jammer to be optimized to reduce compression loads. For example, they are often used for tack lines on asymmetric spinnakers where they are mounted on the bow and operated from the cockpit.

They are also great for reefing lines and can be mounted inside the boom which removes the need for highly loaded lines back to the cockpit. This in-line operating mechanism also means the jammer can be mounted in small, inaccessible spaces.

Simple separation of body and base - Due to its clever design, the body is held to its base by only a single screw and can be separated from the base in less than 30 seconds making regular maintenance quick and easy. It also means the base is easy to mount securely, in difficult to reach locations on the mast, boom or deck, without the body in place.

The Karver KJ Jammer truly stands out from the crowd and its unique features offer some interesting and unique rope holding applications which are gradually being appreciated by a growing number of cruising and club race customers.

Still in two minds?

Don't worry! On our website you can find detailed product information on all our clutches and jammers. If you are still unsure, you can always contact us using our contact form and we would be happy to help.

Related Articles

Tylaska Cone and Plug Fids explained
How to release loaded fittings remotely Tylaska Marine Hardware is an American manufacturer of high quality- marine hardware for the sailing and marine industry. Tylaska's stated aim is to make the best product based upon physics and not economics. Posted on 16 Jan
Velocitek - get your electronics strapped in
Brackets for every possible mounting point Simple, clear and extremely functional. Velocitek electronics are popular among sailors from beginners to competition veterans thanks to their functional design and ease of use. Upffront are big fans of the Velocitek range of electronics Posted on 8 Jan
Tuff Luff head foils care and maintenance
A guide from Tuff Luff's twin-grooved headfoil allows for easy and fast headsail changes. It is a must-have system for any club or competitive race boat. Tuff Luff is owned by Schaefer Marine Inc. who has been in marine hardware design since 1966. Posted on 2 Jan
Soft Attachment Blocks - a guide to the basics
There has been a quiet revolution going on in the last 5 years There has been a quiet revolution going on with block attachments over the last five years. Soft attachments are universally accepted as the preferred method of securing a block. Posted on 25 Dec 2019
Bamar's RLG EVO - Code Zero Furler
Sleek, performance-orientated furling designs investigated Hailing from Northern Italy, Bamar are over 40 years old and on a mission to create sleek, performance-orientated furling designs that aim to 'partially automate sailing operations'. Posted on 19 Dec 2019
Trogear Bowsprits
A good enough reason to drill a hole through your bow Here at Upffront, we talk a lot about asymmetric sails and code zeros, and with good reason! Faster and more manageable, these are a popular choice among many sailors, with one caveat: they require a tack point. Posted on 11 Dec 2019
Loop Woggle is 'The Daddy'
In the world of genoa sheet leads In this blog we look at the trend towards lightweight, flexible sheet lead solutions and why the LOOP Woggle is working its way to the top of the pack in high load situations. Posted on 5 Dec 2019
Andersen Sailing Winches - making the right choice
The key variables and challenges involved in selecting the right winch Andersen winches are a big name in the boating business. Designed and manufactured in Denmark, Andersen Winches have earned a reputation for building high quality, reliable sailing winches that can last a lifetime. Posted on 27 Nov 2019
Calculating your sail areas
When purchasing new hardware this is often a crucial step Lots of equipment on board is load dependant and apart from length and ballast of the boat the primary driver is sail area. It is therefore unsurprising that a lot of hardware manufacturers use sail areas as a primary specification criterion. Posted on 21 Nov 2019
Ino-ending - The end of the line?
Simplicity is key with these blocks When it comes to the Ino-block range, the manufacturer firmly believes that simplicity is key, and Upffront tends to agree with them. Posted on 13 Nov 2019
MBW newsletters (top)