The Tech Deposit Bank is a neutral structure that is basically a superior version of Tech Oil Derricks, providing twice the cash flow when captured by an Engineer. However, it is rarely seen on the battlefield than the Oil Derricks.
The Tech Deposit Bank functions much like the Tech Oil Derrick, but provides double the cash flow and the initial capture bonus. This makes the Deposit Banks structures sought after by all commanders.
As the Tech Deposit Bank is similar to the Tech Oil Derrick in function, most of the strategies associated with the latter apply to the former (such as capturing it as soon as a Barracks is constructed and defending it from hostile Engineers). The exception is that the Tech Deposit Bank does not explode when destroyed unlike the Tech Oil Derrick, so enemy forces can freely close in to destroy this tech structure to cripple its owner's cash flow.
Due to its rarity, the Tech Deposit Bank is a more contested tech structure than the Tech Oil Derrick, so a player who has captured secured one of these is bound to have a big money advantage even in the early game.