A pin latch includes a guide block, a handle having a trigger, and a shear pin housed slidably within the guide block and connected to the handle. The shear pin includes a catch-pin engageable by the trigger, and is slidable between an engageable position and a disengageable position when the handle is moved from a closed position to an open position. Alternately, the pin latch includes a bracket connected to the shear pin and includes a catch-pin, and the handle is moveable to an intermediate position, such that a trigger is disengaged from the catch-pin and the shear pin engages a stop pin. A guide block spring acts on the stop pin to retain releasably the handle in its intermediate position. The guide block includes a finger and the shear pin includes a groove sized and shaped to receive the finger when the pin latch is in an unlatchable position.