The crumbling concrete tower at the Diamond Head summit is symbolic of the state’s sometimes lackadaisical attitude about maintaining older structures.

Needed repairs that might have been inexpensive in their early stages are postponed until fixes become more costly and difficult, sometimes requiring dangerously deteriorating structures to be demolished and replaced.

Concrete pillars holding up the tower at the Diamond Head summit lookout are spalling. Spalling occurs when water, sometimes coupled with salt in the atmosphere, enters concrete and creates cracks on the surface.

The moisture is corroding the reinforcing steel bars and causing them to lose their bond with the concrete. In some corners, pieces of concrete are peeling off.

If the deterioration continues unchecked, the Diamond Head feature visited daily by thousands of Oahu visitors and residents could eventually collapse.

Exposed rebar and crumbling concrete at the Diamond Head summit lookout.
Exposed rebar and crumbling concrete at the Diamond Head summit lookout. Cory Lum/Civil Beat

In an emailed statement, State Parks Administrator Curt Cottrell said, “We do not have the funds now for restoration, but might be able to cobble together funds for a demolition of the most hazardous features.”

Cottrell has pointed out in an email to the Diamond Head Citizens Advisory Group that demolition and restoration will be less costly at this point than repairing the spalling.

State lawmakers created the Diamond Head Citizens’ Advisory Committee in 1977 to help develop a master plan for the Diamond Head State Monument.

In an August 27 email to the committee, Cottrell stressed the importance of addressing the deterioration at the Diamond Head summit soon.

He said it was more pressing to prioritize fixing the deteriorating concrete at the summit lookout because of public safety than to spend an estimated $500,000 for a 12-foot fence he proposed earlier to make it more difficult for homeless vagrants to camp on the upper oceanside slopes of Diamond Head.

Kapiolani Community College adjunct professor Thomas Moore hikes to the summit of Diamond Head every day and said he has watched as pieces of concrete continue to drop off the tower’s pillars.

Visitors at Diamond Head summit lookout stand on a concrete bunker disregarding ‘Keep Off’ signs.
Diamond Head visitors stand on the concrete roof at the lookout, disregarding “Keep Off’” signs. Cory Lum/Civil Beat

Particularly worrisome, Moore said, are pieces that have fallen off the underside of the roof of the tower. “It is maddening. I imagine nothing significant will be done quickly until someone gets hurt or dies,” he said.

Moore said hikers climbing on top of the tower to take photographs of themselves have hastened the deterioration of the already fragile structure.

As a temporary solution, the parks division has placed pieces of plywood on the tower roof’s underside and tied them with metal bands to keep the concrete from falling on top of visitors. One of the bands has already come loose. A sign underneath the roof warns of the danger but most hikers ignore it.

Advisory Committee member Michelle Matson said the Parks Division brought the deterioration at the summit to the attention of the committee about a year ago

“This is a bad situation,” said Matson. “This is dangerous. The state had a year to find a solution but they still have not.”

A key difficulty in addressing the deterioration is the tower’s status as a historic structure, making it subject to more stringent protections than other government buildings.

The formal name of the structure is Diamond Head Fire Control Station. The U.S. Army began building the station in 1908 as an observation station for spotting enemy ships.

Visitors disregard ‘Keep Off’ signs and stand on top the Diamond Head Summit lookout bunker.
A regular Diamond Head hiker said he has watched concrete fall off the underside of the tower’s roof. Cory Lum/Civil Beat

Soldiers working on different levels at the station were there to transmit information to artillery batteries at Ft. DeRussy in Waikiki and mortar emplacements at Battery Harlow on the northern outer slopes of Diamond Head to help target and destroy any ship intent on attacking Oahu.

In the early 20th century, naval attacks were seen as the greatest threat to US national security.

But shortly after the Diamond Fire Control Station was built, it was already obsolete. When Oahu was attacked by Japan in 1941, it was by air not by sea.

Coastal artillery scholar John D. Bennett speculates that the deteriorating tower at the Diamond Head summit was not part of the original construction of the fire control station. Instead, it was probably added to the station sometime after the Pearl Harbor attack in 1941.

“It is an oddball kind of thing,” he said. “It’s difficult to determine its use. It could have been a searchlight tower used to illuminate the sky for anti-aircraft purposes or help spot approaching ships, but I can’t prove it.”

Bennett, a Kaneohe resident, is a former Honolulu Police Department patrolman and former investigator for the Honolulu prosecutor’s office who has become a leading scholar on Hawaii’s coastal artillery defense sites.

It’s painful to watch the current hastening of the tower’s demise by visitors who ignore danger signs on the tower and continue to climb on top, jumping up and down to make their selfies and group photos more dramatic.

Until the parks division finds funding for a permanent solution, it should consider posting an employee at the top to deter such dangerous and damaging behavior by unmonitored visitors. With 3,300 people coming into the crater each day, more should be done to protect the crater itself and the people who enjoy it.

But Cottrell wrote in an email, “The Division of State Parks does not have the staffing capacity to assign an employee at the summit. In addition to the keep off signs, an additional warning sign may have to be installed until a solution is reached.”

If the Department of Land and Natural Resources lacks the money to fix the damage before someone is injured, what about soliciting additional money from the Hawaii Tourism Authority or visitor industry companies? They make sizable profits bringing in hundreds of thousands of tourists to enjoy Diamond Head.

There has been a lot of talk, but little seems to have been done by the state to enlist the help of HTA and tourism companies to help mitigate damage to Hawaii’s parks and wilderness trails from the 10 million visitors arriving in the state each year.

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