critical and ultimate depths

d) Deterioration factorStatutory regulations in South Africa state that thevalue of B for a rope must never fall below 0.9 of theinitial (as new) value of Bie,.B present2 0.9.8 newIn this paper all safety factors laid down by Statutehave been increased by the factor D before payloadshave been calculated.

e) Critical and uttimate depthse.1 ) Drum winders

e.2) BMR winders

e .3 ) Koepe winders

Fig 16 Photograph of installation Nos 4 or E (Appendix ll)

t-4) Range factor {Koepe only)

p aL\J-u.w I*; - ,l ks(/ l- l) ll ar -l '-D

Duty Depth(m)

Grade of steel in ropeMPa

I 7s0 I 800 I 9s0 2 000 2 050Men

Mineral

CriticalUltimate

CriticalUltimate

1 s80 1 619 | 1r3 r 760 1 8003 160 3 240 3 430 3 520 3 600| 160 1 803 I 909 1 960 2 0023 520 3 605 3 815 3 920 4 000

.\len

\l inererl

CriticalUltimate

CriticalUltimate

15803 160

r 9413 700

1 6193 240

I 9893',l90

I 7133 430

2 1054 015

| 7603 s20

2 1644 125

1 8003 600

2 2r04 220

Duty

t,1 r'n

T :.era.l

Depth(m)

CriticalUltimateMin FOS

CriticalUltimateMin FOS

Grade of steel and No of Ropes

I 750 MPa I 800 MPaI rope 2/3 ropes 4in ropes I rope 2/3 ropes 4/n ropes1000 1415 18352 06A 2 250 2 470

1 .s 6.8 75 6.2s1000 141s 18402 290 2 s00 2 7506.7 s 6.19 5.62

1 0002 120

7.5

I 41s 1 8352 320 2 5406.87s 6.2s

1 000 I 415 I 8352 3s0 2 s70 2 8206.7 5 6.19 5.62

-t

I

FormulaeDrum winders

,fur)e -

w

e8r DF(t+ 1)>P=-BMR winders

tlwD