Demounting and Reinstallation Procedures

Demounting Procedure

In the event that a section of Brifen safety barrier needs to be lowered to the ground in order to provide emergency access, the following procedures should be followed.

UNDER NO CIRCUMSTANCES should tensioned wire ropes be cut. This applies to tensioned wire ropes in any situation. Cutting them could result in the ends flailing around unpredictably which could cause serious injury to the person cutting them or someone close by.

It is not generally necessary to detension a Brifen safety barrier in order to lower the ropes to the ground. This means that the barrier can subsequently be reinstated without the need to carry out any retensioning.

  • The first step is to lift the two upper ropes out of the short slot in the top of the Brifen posts and place them one either side of the of the posts making sure they run parallel through the section to be lowered. Because the slots in the Brifen posts are very shallow, one person can easily carry out this procedure unaided.
  • Most maintenance crews carry a simple spreader bar which they use to speed up the replacement of Brifen posts following vehicle impacts. If one of these spreader bars is available, it will also speed up the following steps.
  • If a spreader bar is available, insert it alongside one of the Brifen posts, and turn the spreader bar through 90 degrees in order to spread the Brifen ropes apart. The post can then be lifted upwards clear of the ropes. The spreader bar is then removed. After the first post has been removed, the barrier will appear as shown in fig.2.
  • If a spreader bar is not available, the ropes can be spread apart by hand, although this may sometimes require two men spreading the ropes while a third person lifts out the Brifen post. The easiest way to spread the ropes is to pull the ropes away from one side of the post, while using one or both feet to push the ropes away from the opposite side of the post. After the post has been removed, care should be taken to release the pressure on the ropes slowly. If possible, gloves should be worn to protect the fingers.
  • 5.Repeat step No. 3 with the second post along, i.e. not with the immediately adjacent post. Continue to remove every second post until approximately 10 posts have been removed. The barrier will now appear as shown in fig. 3.
  • The ropes will no longer be interwoven around the posts which have been left in position. Now lift the ropes off the plastic pegs and allow the ropes to fall to the ground. The remaining posts can then simply be lifted out.
  • The posts which have been removed can now be stacked up at each end of the emergency crossing point in order to hold the ropes on the ground. If a longer crossing area is needed, more posts can be removed using the above steps.

Reinstallation Procedure

  • The first step is to identify the two lower ropes and ensure that they are lying on the ground without any crossing over. Then, every second post can be replaced in its socket, such that the two lower ropes appear as shown in fig. 3. The two upper ropes should also run along one side of the posts.
  • Lift up the 2 lower ropes and hang them on the plastic bobbins. The upper ropes are best left lying on the ground until step 5.
  • Starting from one end, the remaining posts can now be installed, one at a time. To do this, if a spreader bar is available, use the spreader bar to make the two lower ropes cross over. By turning the spreader bar through 90 degrees, the ropes are then spread apart enough to allow the post to be replaced.
  • If a spreader bar is not available, the 2 lower ropes can be crossed over and spread apart manually, as outlined in step 3 of the demounting procedures.
  • Repeat step 3 to replace each of the remaining posts.
  • Finally the two upper ropes can now be repositioned in the slot in the top of each post. The plastic caps can then be replaced, and the Brifen barrier is fully operational.

For further details contact Paul Childs

Ph. 09 2744299 or Mob. 027 4741603