I understand that the green shirts are in charge of catapult maintenance, but why are they the ones that remove the arresting cable on US aircraft carriers? White shirts are the landing officials, so why aren't they in charge of removing the cable? Also, could you clarify the process of removing the arresting cable? I downloaded a pdf explaining the meaning of the jerseys, but it didn't clarify this question. Thank you.
The simple answer as to why "white shirts" don't remove the cable is that the Navy, like any organization, assigns duties based on skills and training. The skillsets required for catapult and arresting gear maintenance are similar, so it makes sense that personnel preforming these duties are lumped together in the same functional group.
I believe the "landing officials" you mention is referring to LSOs, or Landing Signals Officers. (I was one once...) LSOs are pilots first, assigned to deployed squadrons, who fly regularly but also receive specialized training on the intricacies and dynamics of recovering aircraft at sea. Every fourth day during flight operations the LSOs will stand duty on the flight deck.
Interestingly, white shirt personnel are not interchangeable like some others are. While most shirt colors contain groups of personnel trained in the same occupational field, white shirts are actually a catch-all color for other miscellaneous flight deck personnel. For example, LSOs just happen to wear white - that doesn't mean we are qualified to fill a medical or QA role, or replace liquid oxygen bottles. Those tasks require similarly specialized skills and training.
Of note, if you look at photos or videos of LSOs you may note that some are in Khaki trousers with white turtleneck flight deck jerseys and float coats, while others are in flight suits. The team on duty generally wears the khaki and white, but there are often LSOs in training up there to observe, and sometimes you will be scheduled to fly on a duty day, hence the mix and match of uniforms.
Now, let's get to the process of "removing the arresting cable". This could be interpreted a couple of ways as the comments indicate. If by this term you mean unhooking the cable from the aircraft tail hook, this doesn't require a person to go actually manually unhook it. The way it works is as follows:
Once the aircraft is at a full stop the pilot is signaled by a yellow shirt, (aircraft director) to throttle back to idle and release brakes.
A signal is then given, (and seen by the pilot) to "pull back" the cable.
A hydraulic pump is activated by deck edge personnel and the arresting gear cable begins to retract, pulling the aircraft to the rear.
Once the aircraft has a little rearward momentum, the director signals for arresting gear retraction to temporarily halt while the aircraft continues to roll backwards.
As soon as the hook is clear of the wire the pilot is given the hook up and taxi forward signal. The gear is then fully retracted into battery for the next landing.
If, however, by "removing the cable" you meant physically removing and replacing what we call the CDP (for Cross Deck Pendant) because it has become kinked or has broken strands, (my first interpretation) well that is a different process entirely. And it's one that happens amazingly fast during the heat of a flight operations with potentially low fuel state aircraft in the pattern overhead.
If a CDP cable takes a couple hard hits and is deemed unserviceable:
Two green shirts will run out to disconnect it, drag it to the side, and pitch it overboard.
Two more will follow on their heels with a new one from the spares along the starboard side, and hook it right up to the fittings at the end of the spools below decks.
If done correctly, (within a minute or two) sometimes only a couple planes may need to be waved off for a foul-deck before the recovery cycle resumes.
Replacing a CDP is dirty, nasty, work. The cables are loaded with grease, and if frayed may have sharp strands of metal. When done efficiently it happens fast, like a racing pit stop... And it would make as much sense to pull an ungloved, specialized Pilot/LSO off the platform to do it as it would to have a NASCAR driver jump out of his/her race car to fill it with gas during a pit stop, or expect a major airline captain to stop and change a tire in the midst of doing cockpit pre-flight checks.