Holding Power
Ratchamatic blocks allow hand holding loaded sheets. The eight-sided faceted sheave grips loaded sheets yet
allows a line to be eased instantly with control. They allow the crew to hand hold main, jib, and spinnaker sheets
with only a faction of the effort that a regular block requires.
Holding power varies according to sheave size and type.
57 mm Ratchamatic blocks
with eight-sided faceted sheaves can provide up to 10:1 holding power.
57 mm
Power3 Ratchamatic blocks
with added facets offer increased holding power. See chart below.
75 mm Ratchamatic blocks
with eight-sided faceted sheaves
can provide up to 15:1 holding power.
Holding power ratios are determined using a 180° wrap angle and can very according to line type, and line
condition.
Ratchet direction:
Arrow on side of block shows direction that
sheave will spin in ratchet mode. Refer to arrow when
reeving block or mounting cheek block.
57/ 75 mm block no
.
Sheave color
Holding power 57 / 75 *
Sheave image and facet count**
2625 - 57 mm
2680 - 75 mm
Black
10:1
15:1
Example: Block holds 45 kg (100 lb) load with 4.5 kg (10 lb) of effort
2165 - 57 mm
2175- 75 mm
Titanium
(tan)
15:1
22:1
Example: Block holds 67.5 kg (150 lb) load with 4.5 kg (10 lb) of effort
2168 - 57 mm
2177 - 75 mm
Silver
20:1
30:1
Example: Block holds 90 kg (200 lb) load with 4.5 kg (10 lb) of effort.
8 facets
60 facets
45 facets
*Holding power ratios are determined using a 180° wrap angle and can very according to line type, and line condition.
Depending on line composition and cover texture, the more aggressive sheave facets can increase line wear.
**The 2770 sheave has fewer facets than the 2168 and gains more holding power by having more prominent ridges.
Using Ratchamatic
®
Block
Low load -
Sheave spins
either direction
Higher load -
Sheave spins in
direction of arrow
Adjusting Ratchamatic
®
INSERT
2.5 mm hex wrench
(included)
ALIGN HOLE
in sheave
with bottom of block
HEAVIER
LOADS
LIGHTER
LOADS
Remove becket to access ratchet
adjustment hole.
Power3 Ratchamatic
®
Blocks - Holding Power
Power3 Ratchamatic
®
blocks offer three options of faceted holding power to best take advantage of the day’s wind
and wave conditions.
Ratchamatic
®
blocks spin freely in both directions under low load. At higher load, ratchet engages, and sheave facets
provide holding power. As the load decreases, the ratchet shifts back into light air mode and free spins. Unloaded main
and jib sheets run out freely during mark roundings and asymmetrical spinnakers run free during jibes.