What mechanism is used to adjust the height of the net during an arrestment on a BAK-15?

The lever chain hoist is the appropriate mechanism used to adjust the height of the net during an arrestment on a BAK-15 system. This type of hoist allows for controlled lifting and lowering by utilizing a chain and lever mechanism, which provides the operator with the necessary leverage to adjust the net's height securely and efficiently.

Using a lever chain hoist is practical in this context because it allows for fine adjustments in height, which is critical for ensuring that the net is positioned correctly to facilitate safe and effective arrestment. The manual nature of the lever chain hoist also provides reliability and ease of use, ensuring that operators can quickly make adjustments in operational scenarios.

Other mechanisms listed would not offer the same level of precision or control needed in this situation. A winch system may be effective in other weight-lifting scenarios but can be less precise for small adjustments. A pulley system is typically used for altering the direction of force rather than adjusting height with precision. Additionally, a net tensioner is designed to maintain tautness rather than to adjust height, making it less suitable for this specific application.