Most logging track, especially that track going into the forest where the trees were harvested was pretty rough. Max speed would be somewhere around 10mph, or less.
Make your run longer by running the tracks between the saw mill and the forest in tightly twisting "S" curves providing your locomotives can handle the tight curves.
I think what I would try for modeling purposes is to make log loads removable as one piece. It might be 3-5 logs stacked into a triangle and chained together. Run a piece of clear fish line from the center log on the bottom up through the load, & tie a small loop in the end. Bring you log load down to the saw mill, remove the loads with small hook on a stick, & carry them back to the end of the peninsula for loading the next train.
I'd still recommend having one set of loaded cars and one set of empty cars. Spot the empty cars at the mill and the loaded cars at the end of the spur, and have your logging train swap them, then move the cars back after the operating session. That way you don't have to figure out a way to load or unload the cars.
One thing I see: It looks like you can replace that severe Y turnout with a normal LH turnout and not lose any function. You have the space to the right. It would look more flowing and would remove that nasty S curve you've got brewing.
That S curve in the spurs can't normally be eliminated. You could slid the RH turnout to the left and install a bit more straight track in between that turnout and the new curved turnout. Sections of straight track in between two opposing curves tend to eliminate S curve problems. It would shorten the spurs by that much however.
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