25

enter image description hereWhat are the rectangles adjacent to the arresting gear on Aircraft Carriers? Are they service hatches?

https://www.kastalon.com/wp-content/uploads/2017/10/ford-emals-3.jpg

aerojetman62
  • 423
  • 2
  • 6

2 Answers2

36

The rectangles are called impact pads. The ends of the arresting cable tend to snap back onto the deck after an aircraft catches it. The replaceable polyurethane pads protect the carrier deck from the cables.

Impact Pads

Source: NAVEDTRA 14310

As Michael Hall points out, the section of cable across the deck is called the cross deck pendant. Since it takes such a beating, it has to be replaced every 125 arrests. The rest of the cable goes below deck into the arresting engine that uses a combination of hydraulics and pneumatics to absorb the energy. This is the purchase cable and only needs to be replaced after around 1400 arrests.

It's much faster and cheaper to just replace the cross deck pendant, so it's attached to the purchase cable with terminal fittings. These heavy fittings are what can cause the most damage and the pads are located where they most often strike the deck.

Cable Terminals

Source: NAVEDTRA 14310

fooot
  • 72,860
  • 23
  • 237
  • 426
  • 1
    When you say "after the aircraft catches it" do you mean after the aircraft raises the hook and the cable snaps back or as the aircraft lands, the cable snaps back? – aerojetman62 Jun 05 '23 at 21:19
  • @aerojetman62 it's as the aircraft lands and catches the cable. After it stops and raises the hook the cable is retracted slowly. – fooot Jun 05 '23 at 21:32
  • Good edit. Feel free to steal my photo and I might just delete my answer as yours is more complete. – Michael Hall Jun 05 '23 at 22:59
24

Good answer by fooot already, but to add some detail, it isn't the cables themselves as much as this beefy steel "knuckle" connecting the more readily replacable cross-deck pendant to the much longer below deck cables that run through the sheaves.

Each trap is like cracking a whip, sending a ripple outwards from the hook point, that hammers this thing into the steel deck with quite a bit of force. The replaceable impact pads reduce permanent damage to the underlying structure, and slightly dampen the harshness of the noise below decks.

enter image description here

Michael Hall
  • 25,964
  • 2
  • 62
  • 99
  • Yes, I could see how that could cause quite a bit of erosion and damage to the flight deck after an extended period at sea. I guess the pre-existing flight deck coating that is applied prior to deployment and periodically replaced is insufficient in those areas. – Romeo_4808N Jun 07 '23 at 03:42
  • Neat point about noise below decks. If it's not too hard, could you drop in a link of the sound of these cables slapping onto the pads? – Kenn Sebesta Jun 10 '23 at 12:23
  • I’m afraid I didn’t make any recordings… – Michael Hall Jun 10 '23 at 14:21