Loading Ultramax with ships gear uses more man power,Each shift...

Loading Ultramax with ships gear uses more man power,Each shift will consist of at least 4 crane drivers,a couple of Dozer drivers on the barges,a deckhand and a Supervisor.
Loading is a bit more complicated as its 5 hatches with 4 cranes
No large barges .
Using smaller barges increases crane downtime ,mooring, unmooring.At least you can put an full barge on the opposite side of the empty barge which minimises downtime.
If the ship starts to roll, unless a static tow is used to keep the ship on a heading that eliminates the roll cargo work will cease.(10t of grab and product swinging like a pendulum is interesting to watch and can cause an amazing amount of damage to the gear and the ship!)
A metre swell in the wrong direction will probably halt or slow loading to a crawl.
Probably TSA are having to train up crane drivers on the job as many of the old teams will have got jobs elsewhere when the TSA Skardon came on the scene.
So maybe the unit cost is higher initially but once the loading rate rises the unit cost will decrease again.
I am certain that the present management would not have engaged in using the Ultramax option to increase exports without doing the numbers .