Built of concrete and steel rebar, the six-story Fire Control Tower No. 23 in Cape May Point is an imposing reminder of a time of fear.
As the Nazis stormed through Poland in 1939, the U.S. Army began planning a ramp up of coastal defenses. The Delaware Bay, with its busy shipping lanes from the port of Philadelphia, would be an easy target if the country entered World War II.
"They were afraid the Germans would stand off the mouth of the bay and bombard ships coming in and out," said Robert Heinly, who oversees tours of the six-story sentinel for the Mid-Atlantic Center for the Arts and Humanities.
Heinly said Fire Control Tower No. 23 was built to help monitor the bay, relaying the locations of suspected enemy ships and aiding gun crews in the event of an amphibious invasion.
Constructed over a few weeks in 1942 at a cost of $24,700, the tower at the mouth of the bay was part of a coastal defense system that included three similar towers in Cape May and the Wildwoods, two 6-inch guns at the nearby Battery 223 and three batteries, equipped with 16-inch guns - the largest guns on U.S. Navy battleships in World War II - and another 11 towers across the bay at Fort Miles in Delaware.
The tower, with a foot-thick roof and walls, was built to handle the worst the Nazis had at their disposal.
"This was built to take a direct hit from a 16-inch battleship gun or a 500-pound bomb," said Heinly, who serves as MAC's museum coordinator. "That was some heavy-duty construction, although too many of those direct hits and eventually it would go."
Robert Russell, the Bridgeton architect who oversaw a 2003 restoration project of Fire Control Tower No. 23, said the towers were at the cutting edge of concrete construction at the time.
After a couple weeks spent grading the site and laying 11-foot deep concrete pilings, the actual tower was poured in a matter of days. Russell said the towers were designed to be built very fast using a process called "slip forming," in which concrete is poured into a moveable form.
"It was almost like two barrels, one inside the other, and you poured the concrete in the space between," he said. "They keep jacking the form work up as they went so the tower was actually poured . . . in no more than a week's time."
And while the 13 towers that remain of the original 15 along the Delaware and New Jersey coastlines appear identical at first glance, each differs in subtle but important ways.
Some are taller than others, which Heinly explained was a function of the elevation of the land on which they were built. No. 23, which was built a few hundred yards from the beach in a low-lying forest, was among the tallest at 71 feet. That's about half the height of the nearby Cape May Lighthouse, at 157 feet tall, which was also used by the military as an observation point.
"You have to be able to see as far as your guns can fire and the curvature of the earth only let's you see something like 15 miles from ground level," he said. "They built them six stories tall to cover their entire range."
Heinly said the 16-inch guns had a 26-mile range.
Poured concrete floors - another feature not found in all the towers - included a staggered ladder system, which Heinly said ensured "if you fall off, you only fall one floor and not six." The ladders could also be retracted in the event of enemy landfall, he said. A manhole-size hole through the center of the tower accommodated a pulley-system for supplies.
The concrete of No. 23 featured a unique blend of locally mined sand that proved particularly hard, Heinly said.
"Our contractor made a comment about the unusual number of drill bits he wore out drilling into this concrete because it was really tough," he said.
Meanwhile, Russell said other building materials were chosen for purely financial reasons.
"There were a number of designs that were proposed by the Army and the towers varied as the designs evolved," he said. "For instance, the tower in Cape May had wood doors on it whereas early towers had steel doors - because steel was becoming scarce due to wartime construction."
Other differences - such as rooftop versus indoor observation platforms and horizontal versus vertical windows - are harder to explain.
"It's really hard to tell what the original designers were thinking," Heinly said.
How the towers were used also evolved over the course of the war, he said. Early in the war, with a number of merchant ships being sunk offshore, Heinly said the men stationed there were on the lookout for both submarines and surface vessels. They also could be useful as spotters in the event of an air raid or large-scale invasion.
Men stationed at the various towers would calculate the azimuth, or the measure of the angle between a target ship and a reference point along the horizon, with a telescope. Using the known distance between the two reporting towers, the location of the target ship could be triangulated and the coordinates used to sight guns on either side of the bay.
But Heinly said the men stationed at the towers had relatively few opportunities to use their skills at sighting enemy ships.
"Ironically, by the time all of this was finally completed, it was obsolete," Heinly said. "They were built to defend against surface ships, air raids or a German amphibious invasion, but certainly by mid-1943, we knew that wasn't going to happen."
And anxiety over submarines - which the towers provided little protection from because German captains wouldn't risk surfacing during daylight - also subsided.
"Early in the war, German U-boats had a huge technological advantage over anything we had," he said. "But with better sonar and depth charges, pretty soon the balance had shifted. There was a much higher mortality rate for sub crews than the merchant ships by '44 or '45."
Mike Rogers, a Fort Miles historic interpreter from Millsboro, Del., said the armaments guarding the Delaware Bay were built with a "World War I mentality" that involved ground invasions and surface ships.
Although Adolph Hitler built large battleships designed to intimidate other nations, Rogers said they kept mostly close to home. But even the submarines, which were the greater threat to the eastern United states, tended to operate 30 miles off shore.
"The Germans never really got close enough for us to engage them," said Rogers, 32. "We were prepared, but we were prepared for the previous war."
Heinly said the Army soldiers at the tower were gradually replaced by U.S. Coast Guard auxiliary and Merchant Marines. Typically, 10 men were stationed inside the tower for 10-hour shifts, with six of them manning the telescopes on the sixth floor at any given time while others rested on the fifth floor, which was equipped with cots and a pot-bellied stove.
"It was hot in the summer, cold in the winter," he said. "They were thankfully bored, which beats the hell out of getting shot at."
When not on duty, he said officers stayed in quarters near the Cape May Lighthouse and enlisted men were stationed at the Saint Mary-by-the-Sea retreat.
After the war, the tower became a popular hangout for high school kids.
"Back then, it was just smoking cigarettes and messing around with their girlfriends," he said. "But as the years went on, it got a little more serious than that."
Eventually, the tower was sealed off to prevent accidents or further vandalism, and so it remained until the last decade, when a group of concerned citizens mobilized to restore the building. In 2003, it was placed on the National Register of Historic Places and in 2009, after a $1.3 million renovation project, it was reopened to the public.
Russell, who supervised the restoration starting in 2004, said all the wood and windows were laying inside the base of the tower. There were no interior stairwells and some of the concrete had been damaged.
"Salt and the air from the ocean penetrates the porous concrete and attacks the steel," he said. "The steel rusts and expands and pops the concrete, similar to what you'll see on a state highway bridge."
After the concrete was repaired, Russell said the fittings were replaced as closely to the original specifications as possible and a series of interior spiral staircases were constructed to accommodate visitors.
Russell, of HMR Architects, said the assignment had special significance because his father served on the U.S. Army Signal Corps during World War II.
"It's very interesting for me to go down there now and see the vets who man it now and come to visit," he said. "You see how they relate to it and that it's a special part of their lives. It's fun to see it come alive."
Beyond the important role the tower plays in educating the public about World War II, Heinly said it also served an important role in the war itself despite the fact the amphibious invasion it was built to head off never came.
"What they were effective in doing was to force German subs to stay under the surface during the day, which meant if they wanted to attack a merchant ship, they had to torpedo it," he said. "In some ways, that was viewed as wasting a torpedo since the preferred way to deal with unarmed merchant ships was to surface and hit it with your deck gun."
Heinly said there were about 18 ships sunk directly off the mouth of the Delaware Bay and several dozen off the coast New Jersey.
"They were also effective in that we could get people from the Navy base out there and into the area to locate the sub, and it also enabled us to get help to survivors quicker."
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