I'm surprised removing scrap metal is that complicated/expensive. Tonga has a container port, and I'm guessing they tend to receive full containers and send back out empties.
Some places find ways to take advantage of this, e.g. Canada exports most of it's bean/pulse crop in bags to Asia in containers instead of bulk carriers. Wasn't that long ago we did the same with scrap metal (maybe still do).
Certainly a crusher/cuber helps maximize density, but a torch or other cutting tools can go a long way to save space. And you're mainly paying for weight anyway as the empty is a sunk cost.
Some places find ways to take advantage of this, e.g. Canada exports most of it's bean/pulse crop in bags to Asia in containers instead of bulk carriers. Wasn't that long ago we did the same with scrap metal (maybe still do).
Certainly a crusher/cuber helps maximize density, but a torch or other cutting tools can go a long way to save space. And you're mainly paying for weight anyway as the empty is a sunk cost.