covering, whilethe strength ofthe ropelies solely inits
internalpartwhichisalsobraidedandisknownasthecore
(d).Bothtypesofropehavetheirownspecialcharacteristics
whichmakethembettersuitedtocertainapplications;twisted
ropeislessflexibleandbetterforheavy-dutywork,whereas
braided rope isa lot softerand if pre-stretched does not
expandanyfurther.Ropeshouldbeboughtwitha viewto
choosingthemostsuitabletypeforthejobyouhavein mind.materials
The characteristicsofa rope obviouslydepend toa great
extentonthefibersthatmakeit up,soitisusefultoknowwhat
thecharacteristicsofthedifferentmaterialsare.Fromthisyou
candeducethoseofthecorrespondingrope.
Thenamesofthematerialsmaybesomewhatconfusedas
chemical names like polyester are freely mixed with the
manufacturer'sbrandnamessuchasTergal.Dacron,etc.The
followinglistgivesonlythechemicalclassificationsandthe
tableonpage 14 givesthemostcommonbrandnamesforthe
equivalentproducts.It shouldalsobenotedthatmanufactur-
ingcompaniesnowoffermanyvariantsofthesameproduct
(withgreaterorlessstrength,elasticityetc.).Thefollowing
datarefertoaveragecharacteristics.
a.fiber b.yarn c.strand d.core e.sheath
1 and2.twistedrope 3.braidedrope