The Blocstop™ BSA fall arrest device is an additional safety component designed to stop a suspended platform in the event of a fall. It is specifically intended for use on man-lifting suspended platforms equipped with two manual or electric hoists. The device operates automatically, engaging the safety wire rope if a hoist fails, the lifting wire rope ruptures, or if the platform experiences a significant inclination.
Function Description:
The Blocstop™ BSA device consists of a zinc-plated steel housing and a zinc-plated steel lever with a detection roller at its end. It is rigidly mounted on the suspended platform using two screws and self-locking nuts. The lever rotates to open and close the jaws that grip the safety wire rope.
The device's operation is entirely automatic and depends on the distance 'f' between the lifting wire rope and the safety wire rope.
- When the lifting wire rope is tensioned: The lever keeps the jaws open, allowing the safety wire rope to slide freely through the unit (Fig. 7).
- When the lifting wire rope becomes slack: The lever, pushed by its internal return spring, swivels. This action causes the jaws to clamp onto the safety wire rope, immediately stopping the suspended platform on the side where the fall arrest device is installed (Fig. 6).
Actuation of the lever and subsequent clamping can be triggered by:
- Rupture of the lifting wire rope (Fig. 8).
- Failure of the lifting hoist.
- Loss of tension on the lifting wire rope due to blockage or snagging during descent (Fig. 8).
- A lateral inclination exceeding 14° relative to the horizontal (on platforms with a hoist at each end) (Fig. 9).
A zinc-plated steel wire rope guide ensures that the lifting wire rope remains in constant contact with the detection roller. Each device is factory-adjusted, and it is strictly prohibited to alter the adjustment of the lever relative to the housing, as this would void Tractel's liability.
Important Technical Specifications:
The Blocstop™ BSA fall arrest device is designed with a usability factor of 4. Each unit undergoes functional testing at its working load limit before shipment.
| Model |
WLL (kg) |
W (kg) |
Øc (mm) |
St |
R (kg) |
| 15.301 |
600 |
4 |
8.3 |
5 x 19 |
4800 |
| 20.300 |
600 |
6 |
8.3 |
5 x 19 |
4800 |
| 15.303 |
800 |
4 |
9.5 |
5 x 19 |
6400 |
| 20.303 |
800 |
6 |
9.5 |
5 x 19 |
6400 |
| 20.304 |
1000 |
6 |
10.2 |
5 x 26 |
8000 |
| 20.301 |
1200 |
6 |
11.5 |
5 x 26 |
9600 |
| 35.304 |
2000 |
10.6 |
14.3 |
5 x 26 |
16000 |
| 35.30 |
2400 |
10.6 |
16.3 |
5 x 31 |
19200 |
- WLL (Working Load Limit): Maximum load for man lifting.
- W (Weight): Weight of the fall arrest device.
- Øc (Wire rope diameter): Diameter of the safety wire rope.
- R (Minimum tensile strength): Minimum tensile strength of the wire ropes.
- St (Structure): Structure of the wire ropes.
The wire ropes, ordered separately, are supplied on a reel with a safety hook (item A, Fig. 16) or with a sleeved and thimbled end (item B, Fig. 16) upon request. Only wire ropes specially designed by Tractel for these fall arrest devices must be used to ensure safe operation.
Usage Features:
- Installation: The device must be oriented vertically with the detection roller upward and mounting holes downward (Fig. 1). It must be rigidly secured to the suspended platform, ensuring a specific distance 'f' between the safety wire rope and the lifting wire rope, as specified in the technical data. The anchoring point of the safety wire rope and the device's fixings must have a tensile strength at least four times the nominal capacity of the Blocstop™ BSA. It is prohibited to install the device on a mobile stirrup (Fig. 15).
- Wire Rope Preparation: Before installation, ensure the lifting wire rope is correctly installed on the detection roller and that the safety wire rope is lightly greased with multi-purpose off-the-shelf greases (no molybdenum disulfide or graphite additives). The safety wire rope's wear must be less than 10% of its nominal diameter (Fig. 20), and it should show no deformation or damage.
- Assembly and Operation: The suspended platform should be aligned with suspension points. The lifting and safety wire ropes are secured, with the safety wire rope hanging freely next to the lifting wire rope. The fall arrest device is unlocked by raising the lever (Fig. 17). The lifting wire rope is placed between the detection roller and the wire rope guide (Fig. 18). After tensioning the lifting wire rope by raising the platform 0.1-0.2m, the safety wire rope is manually inserted through holes A and B (Fig. 1) and tensioned. The safety wire rope must be ballasted with a weight of 9.5 kg for BSA15/BSA20 models and 2 x 9.5 kg for BSA35 models, positioned 0.2m from the ground (Fig. 19).
- Automatic Operation: Once installed and checked, the fall arrest devices require no operator action during ascent or descent.
- Safety Checks: During lifting, continuously check that the safety wire rope slides freely. If not, the jaws must be opened. If automatic opening fails, verify ballast weight positioning. During descent, ensure the safety wire rope slides freely; if not, perform a slight upward movement to re-tension the lifting wire rope and open the jaws.
Maintenance Features:
- Periodic Maintenance and Inspection:
- Fall arrest device: Annual functional check, cleaning, and lubrication by Tractel or an approved repair agent.
- Wire ropes: Weekly inspection by a technician for wear (<10% of Øc) and damage, following the lifting system manual.
- Inclination limiting function (BSA): Daily check by a technician. Incline the platform until the lower hoist's fall arrest device locks, then recover the load on that hoist. Repeat for the other device. This check must be performed with the platform no more than 0.5m off the ground.
- Detection function for lifting wire rope rupture/hoist failure (BSA): Daily check by a technician. Place the platform on the ground and verify that the fall arrest device jaws lock.
- Attachment system (BSA): Daily check by a technician for absence of deformation on the connecting stirrup and tightening of mounting nuts.
- Post-Fall Inspection: If a fall has been stopped, the entire lifting system must be inspected by a technician.
- Removal and Storage: Before removal, the fall arrest device must be unloaded, and the platform or load placed on the ground. The safety wire rope ballast is removed, and both wire ropes are extracted from the device. The device is then detached from the platform, cleaned, greased, and stored. New locknuts are recommended for each reinstallation.
- Malfunctions: A detailed table of malfunctions, diagnostics, and corrective actions is provided in the manual, including instructions to immediately stop operations, secure the load, and, if necessary, return the device to Tractel or an approved repair agent for inspection.
- Markings: Each device is engraved with a technical reference, manufacturing year/month, serial number, and "Made in France." A label provides additional information such as model, wire rope diameter, WLL for man lifting, and a symbol indicating the obligation to read the manual.
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