Using Alternate Line, Knots and Splices
Harken is not liable or responsible for use of line used to secure blocks. Go to Harken Limited Warranty at
www.harken.com for complete details. The following guidelines are offered to help make line choices. It is
your responsibility to choose the correct line for the block. If you are not comfortable choosing line, work
with a qualified rigger or use Harken-supplied Loops 2148 or 2151.
When choosing line, use a breaking
load that is at least double the block’s breaking load to account for factors that degrade line strength.
Factors That Degrade Line Strength
Knots
– Only 60% or less of the line breaking load.
Knots Using Spectra
®
or Dyneema
®
–
Can slip at less than 20% of the breaking load. Use specialized
knots. Lock stitch tail to standing part.
Splicing by a Qualified rigger –
Correctly using a “Bury” splice with lock stitching or a locked “Brummel”
can provide over 90% of the line’s breaking load. Other splices can have a much lower breaking load.
UV Degradation –
UV rays can reduce line breaking load considerably. In high UV areas, lines can be only
60% of the original strength after five years.
Chafing –
Chafing depends upon the amount and can only be controlled through careful installation
practices and constant inspection.
WARNING! Improper knots or splices can weaken the block installation causing it to break suddenly
at high loads, possibly causing an accident, damage to your vessel, personal injury or death.
WARNING! Failure to account for loss of strength due to chafe or UV damage when choosing
line can result in line breaking suddenly at high loads, possibly causing an accident, damage
to your vessel, personal injury or death.
Harken
®
equipment is designed for minimal maintenance. However, some upkeep is required to give
the best service and comply with the Harken
®
limited warranty.
Keep your equipment clean and free-running by frequently flushing with fresh water. Periodically
clean with mild detergent and water solution. Spin sheaves to distribute soap solution evenly.
Flush with fresh water.
Important:
Exposure to some teak cleaners and other caustic solutions can result in discoloration
of part and is not covered under the Harken warranty.
Warranty
For additional safety, maintenance and warranty information see www.harken.com or the Harken
®
catalog.
Maintenance
4369.W/02-17-11
Read important information on choosing line, knots and splices. Go to US Sailing article:
http://offshore.ussailing.org/Assets/Offshore/SAS/PDF/Article.pdf
Go to online manual at www.harken.com/manuals for link.
Part No.
2148 (40mm)
2151 (57mm)
Strands
lbs
kg
lbs
kg
4
600
272
1190
540
Minmum Breaking Load for Line to Make Loop
Four (4)
Strands
