How did they build tunnels or bunkers so fast with out any one taking notice of what was going on around them?
One of the first things the engineers did to hide the nature of the works was to make it look like it was a quarry. This way it would not be bombed by the enemy and no one would take any notice of soil coming out .In North Queensland many hundred of thousands of cubic metres were needed to build Garbutt, Stockroute, the Bohle strip and to bring camp areas above the flood plain.
The fastest way to build a tunnel is to have as many portals as possible being worked at the same time. One at each end and others from shafts along the route which can later be used for ventilation was their usual method, thereby reducing the distance which tunnellers and spoil have to travel underground.
To give an example of what can be achieved; at Tinian in the summer of 1944 THE SEABEES built one of the largest air bases in the world for the B-29’s. Six runways were constructed, each a mile and a half long. There were 29 miles of connecting taxiways and hard standing for 626 planes. Two smaller strips were also laid down, along with 1000 buildings, fuel, ammo and storage dumps with the necessary utility systems. The construction called for the removal of more than 11 million cubic yards of earth and coral.
Astonishingly, all of the Tinian runways were completed in less than eight weeks. If this was able to be done in that time period it would not take long for any of the bunkers to built, given the skills of the Seabees units and the allied works council, taking into account that 85 % were trades people who had worked in the fields of tunneling, road building etc .
It is an incredible effort of the United States Seabees, the Allied Works Council and the Civil Construction Corps. It has long been noted that the Seabees are Americas most decorated units and were able to overcome the worst that could be thrown at them, working in some of the worst conditions every known to mankind.
The photo below shows two tunnels being tunneled into each other. If u looks closely below, you can see the other miner heads peeing through the hole.
BEFORE IT IS COMPLETED, STARTS OUT LOOKING LIKE THIS. THE END PRODUCT IS WHAT YOU SEE HERE.
NOTHING HAS CHANGED.THIS PROCESS WAS USED IN THE 1900’S.