Front View	Rear View	Side View

Technical Details

I acquired my Single Rope Technique Equipment MBA from Single Rope Technique Equipment in 2000.

The Manual Belay MBA has an aluminum pulley sheave fixed between two aluminum side plates. Mine is 57 mm. long, 101 mm. wide, 35 mm. high, and weighs 174 g. The sheave is riveted to the side plates so that it cannot turn and so that the side plates cannot swivel. The latter point was overlooked by the manufacturer’s technical writers: the instructions state "swivel cheek open and insert rope" which is not possible unless one drills the rivet out first - destroying the device.

Each side plate is stamped with "AUSTRALIA," "SRT" inside a map of Australia, "MAX 3000 kG," "SWL 640 KG," "SYDNEY," and "199X3701" where the "X" is obscured by the lower rivet.

Comments

The Single Rope Technique Equipment Manual Belay MBA puzzled me for some time. Their catalog lists it as a belay device, and states that "SRTE Static Pulleys (Friction Pulleys) were designed to be used as a BELAY DEVICE ONLY." The instructions state that "the rope is wrapped 280 degrees, once around the fixed sheave on the MBS and MBA models." Naturally, this wouldn't provide enough friction for a meaningful belay in hard-fall conditions, especially if the MBA was free to turn so that the rope only passed over 100°.

The true intent of the MBA is not described in its own instructions, but in a separate document on SRTE Pulleys. That document contains the following paragraph:

STATIC PULLEYS (Friction Pulleys) - These Pulleys were designed to be used as Belay Devices Only. Although not a true pulley, Static Pulleys (Belay Pulleys) increase the friction between the operator and the worker giving the operator more control… Usually used as the Second Safety Devices.

Although this is still ambiguous, I interpret this to say that the MBA is not intended to be the primary belay device, but is used where the rope is to be redirected so that additional friction is generated at that point. In effect, the MBA acts as a fat carabiner. The instructions state that "MANUAL BELAY [models]… are ideal for use where you wish to increase the surface area in the bight of the rope in case of a fall protecting and increasing the life of your rope" which might support this view, although in the instruction sheet the context of the statement is by no means clear.

Given what I can find out about the Manual Belay MBA from the poorly-written instructions, and given that the only way to rig the rope is to feed the free end through the opening between the side plates and sheave, I cannot recommend this device.

Single Rope Technique Equipment also made an MBS model with stainless steel side plates.

History

Boris Rogelja founded Single Rope Technique Equipment (SRTE) in 1980. Capital Safety Group acquired SRTE in 2011 and their devices started showing DBI-SALA, Capital Safety, and/or Rollgliss™ markings. 3M acquired the Capital Safety Group in 2015 and the Single Rope Technique Equipment markings disappeared.