Charles Ellicott Commentary Ezekiel 26:8

"He shall slay with the sword thy daughters in the field; and he shall make forts against thee, and cast up a mound against thee, and raise up the buckler against thee." — Ezekiel 26:8 (ASV)

A fort ... a mount.—These and the following particulars of the siege indicate the use of ordinary methods, as in the attack of a city on the mainland.

The explanation for this is undoubtedly partly that Palæotyrus (Old Tyre), on the mainland, was approached in the ordinary way, and partly that Nebuchadnezzar must have devised a bridge of boats, or some other method, for approaching the island across the shoal and narrow channel (1,200 yards) which at that time separated it from the mainland.

That if he built a mole, it was afterwards removed is clear from the fact that when Alexander built one 250 years later, sand accumulated on it until the island eventually became a peninsula, connected with the shore by a beach of considerable width.

The buckler is that type of roof made with shields used in ancient warfare by besiegers to defend themselves from the missiles of the besieged. Herodotus (Book 9, sections 61, 99, 102) mentions its use among the Persians.