The unit on top rotates 80 degrees, and a safety system turns it off if it overheats.
From that point on, the 4th was left in the field, although the individual units within it rotated back to Canada every three years.
So the total troop level will rise above 130,000 as new units rotate in and the 4,000 troops are held here longer.
Ideally units and individuals will rotate through each of the three phases.
Numerous units would rotate through for training sessions.
The unit returned home at different times in late 2003 as U.S. forces were drawn down and rotated to meet the changing requirements.
As with any infantry regiment, brigade or division, the units rotated and relieved one another on a routine basis.
In Armor mode, the units rotate around the ship and provide forward cover fire.
It seems that these units rotate every three to four months.
This turret system lets the unit rotate to minimize the effects of sea-swell and wind.