WHAT LIES BENEATH
Underground at Fort Petrie fascinating to columnist
Underground at Fort Petrie fascinating to columnist.
Fort Petrie in New Victoria and Chapel Point in Sydney Mines were two of the seven coastal-defense batteries built around Sydney Harbour at the beginning of the Second World War (1939-1945).
Both were “sister sites,” in that they were built to the same basic plan, especially with regard to their underground layout.
Both forts had two large gun pits, an observation tower, bunkers for searchlights, and several below ground rooms for ammunition and workshops. Each gun pit also had a large elevator, that would carry shells and powder bags from the underground magazine to the surface.
While Chapel Point Battery was closed in 1948, the site at Fort Petrie remained open until 1956.
It was almost 40 years later, in the summer of 1995, that Eric Connors and myself made a successful visit to the underground rooms at Fort Petrie. We did this by means of a vertical concrete ventilation shaft, about 25 feet deep, which had an iron ladder attached to one wall. At the bottom this shaft turned horizontal, and ran for another 20 or 25 feet, until it reached one of the two underground magazines, where the large shells and powder bags were stored.
On the opposite wall of a large room, about 20-feet away, the beam of my spotlight illuminated a vibrant blue colour, which stretched in a band about 4-feet thick, all around the perimeter of the room. Above and below this blue band, the interior of the concrete wall had been finished with a layer of brown bricks. I had not expected this!
About 5-feet below, the beam of light reflected off a layer of water that covered the floor. On closer inspection I was relieved to find out that it was probably no more than two or three inches deep. This was a relief, as local residents had warned us that the lower rooms more than likely had several feet of water in them, that is, if they were not completely submerged.
Three more iron rungs imbedded in the lower wall brought Eric and myself to the floor of one of the two large ammunition storage rooms that made up the lower level of this enormous underground complex. The lights had last been turned off in these rooms back in 1956!
Except for the narrow shaft of light in front of our spot beams, we were in total darkness. I estimated the temperature to be a cool and comfortable 20 degrees, while the third member of our little expedition, Jim Morrison, sweltered in 30 C heat back on the surface. Eric made rough measurements, by pacing off the perimeter of the room, while I took pictures using a very powerful professional flash.
Eric is an engineering technician, with a great deal of experience in concrete and construction work. As we examined the interior of the room with our lights, Eric pointed out the special construction features of this masterpiece of defensive engineering.
“Look at those steel “I” beams in the ceiling, they must be at least 12 inches thick! The space between the beams looks to be covered with iron sheeting, held up by at least 1-inch thick iron bolts. And behind that there is probably two or three feet of reinforced concrete!”
A steel blast-proof door led to a small antechamber, which separated the two ammunition rooms. The other room was exactly the same as the one we had just come from, even down to the man-sized air shaft in one of the walls.
“I’m amazed,” he said, “not only at the quality of the workmanship involved, but even more so at the state of preservation. This concrete is just as good as the day it was poured. No, I lied. Concrete never stops ‘curing,’ so it’s probably even better now than when it was first poured!”
Somewhat reluctant, we made our way back through the air shaft to the vertical ladder that led to the surface. We had been underground for more than an hour, and had been captivated and overwhelmed by this rare chance to examine these long forgotten interiors. And we had the pictures to prove it!