Above, the 6 in steel air pipe is welded to the shelter. Below, the heart and lungs of this 10 ft x 51 ft shelter, the VA-150, is shown with the hand crank installed for manual operation. The 36 in diameter emergency escape tunnel can be compared with the picture above. This exit can also be used as a shower as the open bottom of the vertical shaft is filled with pea gravel and gray water can drain away into the ground.