Black Diamond Superlock (27kN) (v3)

Black Diamond
Superlock (27kN) (v3)

Name:Black Diamond Superlock (v3)
Sub Item:(27kN)
Category:triple-action twist lock
Locking Type:assisted
Unlock Style:lift-and-twist
Sleeve Rotation:90° (unlocked) | 120° (maximum)
Shape:asymmetric D
Nose:notch & pin
Nose Guard:none
Rivets:flat dimpled
Gate Shield:full
Weight:89 g
Dimensions:Length: 121 mm
Width: 72 mm
Gate Opening: 21 mm
Strength Ratings:Major Axis: 27 kN | Gate Open: 9 kN
Other Markings:Forged: BLACK (C-logo) DIAMOND-USA | (ratings) | stamped: (8320) or (3320) or (9320)
Batch Marking Location:spine-exterior
MSRP:$19.95 (1997)
Collection Criteria:★ Mechanically Interesting
★ Manufacturing, Engineering, or Design
Summary:basic twistlock plus manually activated secondary autolock
Description & Commentary:

Uniquely, this carabiner sports a full-autolocking twist-lock stage, followed by a manually activated secondary locking stage. The internal spring forces the sleeve to rotate into a locked position, as is found on basic double-action (single-locking) twist-lock carabiners.

I first learned to belay on this model of carabiner (using a Sticht plate) at a university program. We called the secondary lock supersafe mode.

To manually set the secondary lock, the climber allows the carabiner to close and twist into the locked position, then lifts the twist-locked sleeve until the indexing hinge pin aligns with the cutout. The rotational spring used for the twistlock will encourage the pin through the slot if the climber doesn't prevent it from doing so by over-gripping the sleeve. Spring pressure moves the sleeve downwards, towards the hinge end of the gate.

To disable the secondary lock, the climber must slide the sleeve upwards (towards the carabiner nose) to align the pin again with the cutout, then rotate the sleeve to the twist lock position. Note that the opening between the two modes is in the middle of track for the index pin, minimizing any chance of accidentally bumping the carabiner sleeve out of this secondary lock position.

Former Black Diamond employee Andrew McLean (designer of the Hotwire and The Fin carabiners) had this to say about the BD Autolock:

"It was tricky to build, expensive to produce and jammed up with sand."

I have 6+ examples in four different the Black Diamond stampings - in 4 cases the plastic inner sleeve supporting the outer aluminum locking sleeve has cracked, allowing it to deform. Without the former structure, the plastic sleeve rubs against the outer aluminum sleeve resisting movement under spring pressure alone. Of the carabiners with broken inner sleeves, one example works satisfactorily, but not consistently enough that I would use it in the field.

The carabiners with intact inner sleeves function properly.

The other examples with cracked sleeves range from heavy to light use, with some appearing almost new. This suggests the plastic sleeve may have been a weak point in the design or a problem revealed with age. I wonder if this contributed to the retirement of this design.

Black Diamond sold at least 3 versions of the Superlock with different strength ratings: 28kN, 25kN, 27kN. From reviewing old catalogs, the 28kN is shown in the 1992 catalog, 25kN in 1993, 27kN in 1996 & 1997.

Manufacturer Color:Bright