CALCS PROC038
ROPE STRENGTH

NOTATION

SWLsafe working load (t)
Prnforce-rope, nominal
Npnumber of rope parts, supporting load
Nwnumber of parts, from winch tot part supporting load
Fffactor-friction, 2 or 5
rangeswl range, <10, 10-160, >160:1 2 or 3 respectively
Prforce, rope, factored
FoSfactor of safety
Pbforce, rope breaking

APPLICATION

Luffing & hoist ropes

OUTPUT

Rope breaking load

SEE ALSO

PROC021

THEORY

LR LAME Code Ch2,Para2.4 & Ch3,Para2.27

GUIDANCE

guidance notes

INPUT FORMAT

LET Np=:Nw=:Ff=:range=:SWL=:Prn=:Pr=:Prspec=:PROC038

EXAMPLE

Call Statement

LET Np=3:Nw=4:Ff=2:range=2:SWL=34:Prn=9:Pr=40:Prspec=50:PROC038

Output

PROC038 ROPE STRENGTH, Rev 021095
Pr= Prn*((100+Ff)/100)^((Np/2+Nw)-1)= 9.839
FoS= 10^4/(8.85*SWL+1910)= 4.523
Pb= FoS*Pr= 44.5
UF= Pb/Prspec= 0.89
END038