TM 5-850-1
Table 2-3.
Diameter of Berth (in Yards) Using Standard Fleet Moorings, Riser Chain
Length of various vessels in ft
Depth of water in ft at MLV
100
200
300
400
500
600
700
800
900
1,000
10..........................................
275
340
405
475
20..........................................
280
345
415
480
545
615
30..........................................
285
355
420
485
555
620
685
40..........................................
295
360
425
495
560
625
695
760
825
895
50..........................................
300
365
435
500
565
635
700
765
835
900
60..........................................
305
375
440
505
575
640
705
775
840
905
70..........................................
315
380
445
515
580
645
715
780
845
915
80..........................................
320
385
455
520
585
655
720
785
855
920
90..........................................
325
395
460
525
595
660
725
795
860
925
100........................................
335
400
465
535
600
665
735
800
865
935
110........................................
340
405
475
540
605
675
740
805
875
940
120........................................
345
415
480
545
615
680
745
815
880
945
130........................................
355
420
485
555
620
685
755
820
885
955
140........................................
360
425
495
560
625
695
760
825
895
960
150........................................
365
435
500
565
635
700
765
835
900
965
160........................................
375
440
505
575
640
705
775
840
905
975
170........................................
380
445
515
580
645
715
780
845
915
980
180........................................
385
455
520
585
655
720
785
855
920
985
190........................................
395
460
525
595
660
725
795
860
925
995
200........................................
400
465
535
600
665
735
800
865
935
1,000
This table is based on the following assumptions:
(a)
Length of riser chain is equal to the depth of water at mean high water.
(b)
Ground chains are of length called for by drawings and are pulled taut when installed.
(c)
Anchor drags 90 ft from initial position.
(d)
180 ft of ship's chain used between vessel and buoy.
(e)
Basic formula B = 2/3 (D + L + C1). Where:
B = diameter of berth in yd.
D = depth of water in ft at MHW.
L = length overall of vessel in ft.
C1 = 300 ft (includes 30 ft allowance for increase in radius of berth for drop in waterline due to fall of tide,
180 ft from buoy to ship, and 90 ft allowance for drag of anchor.
Department of the Navy
2-5
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