Pah, reading some of this reminds me of my days on sites in the mid/late 70s.
We used to get a artic load of bricks, you had to unload by hand, no jibs, no hydraulic grabs. Grab maybe 6 or 8 bricks at once and throw them down to your mate who had to catch them and stack them. We'd have a crew unloading a lorry that way, maybe took a couple of hours. I remember one driver was about 60/65, he could pick up more, throw more bricks, for longer than any of us. We were all 17 or so.
Unloading ultra heavy 3x2 paving slabs was the worst, they were back breakers. A whole freeking lorry of them

all by hand.
Artic loads of bags of cement. Not your pussy little 25kg bags you get nowadays,
50kg i should think. Walk up to the trailer, someone on it would lay the bag on your shoulder and you'd walk with it maybe 10 yards to the store...over and over again
Hod carrying ? did that for a bit, whoa, you sway like a tree in a gale at first

it's so wierd.
I remember going home one day and stripping off my shirt as i came in. My mum looked shocked...christ, you're a solid knot of muscle. Wish i still was
Got some memories...and a wrecked back