2015-02-20 / Front Page

Troubled waters

Spring Point Lighthouse needs significant repair
By Duke Harrington
Staff Writer


Spring Point Ledge Lighthouse is in need of costly repairs, and it will be up to its 11-member board how to achieve that goal. (Joe Faragalli photo, www.joefarphoto.com) Spring Point Ledge Lighthouse is in need of costly repairs, and it will be up to its 11-member board how to achieve that goal. (Joe Faragalli photo, www.joefarphoto.com) SOUTH PORTLAND — Spring Point Ledge Lighthouse, One of the most popular and iconic structures along the Maine coast, is in danger of being lost without significant repair to its steel-plate base, which has corroded by as much as 60 percent.

Although a study conducted in October found the 117-year-old caisson-style lighthouse to be in “generally good repair,” the 31-page report includes concern about the deterioration of the lower portion of the structure, particularly in the intertidal zone between high and low tide. Breaches in the flanges between the cast iron plates that make up the exterior of the caisson — an iron tube, 25 feet in diameter, built aboveground and then sunk into the ledge — have allowed water to enter and weaken the integrity of the cement that fills the bottom 30 feet of the structure.

“The lighthouse plating at and below the wind/waterline is freely eroding due to a failed paint system, deteriorated joiner plating, galvanic corrosion and failed bolting,” the report reads. “Interior connecting plates and bolts/rivets between exterior plates have failed with plating cracked or being pushed away from the adjacent structure. The concrete within the caisson is also not helping the situation as there is no access possible to the interior plating, which would be now flooded in any case.”

According to the study, which was prepared by Becker Structural Engineers of Portland, with assistance from Gredell & Associates of Newark, Delaware and Ocean Technical Services of League City, Texas, a “realistic repair scenario” would be to remove the granite breakwater from around perimeter of the lighthouse, allowing access by fabricators who would then install a new series of plates and banding.

However, that work could top $500,000 — a tall order for the trust that’s owned the historic lighthouse since 1998. An annual report available on the trust’s website shows that as of Dec. 31, it had $32,005 in total equity and cash on-hand.

Although South Portland has the lighthouse assessed at $2.07 million, it is held in trust for the public’s benefit and cannot be sold or encumbered. Thus, the 11-member Spring Point Ledge Lighthouse Trust does not count the structure itself as an asset.

“Entrance fees and other sales during the summer are the primary sources of revenues for the Trust, an all-volunteer nonprofit organization,” said trust Chairman Keith Thompson. “The funds required to accomplish these repairs are beyond the amounts generally granted by any single charitable foundation and well beyond what the trust can raise on its own. We anticipate that multiple grants or substantial donations will be required to accomplish the necessary repairs in stages, with the caisson being the most critical.”

However, before that can happen, the trust needs to assess the lower caisson, inaccessible to engineers during the recent study due to the rip-rap installed around the lighthouse in 1934 to percent ice damage, and the 900-footlong breakwater, built in 1951.

Becker Structural Engineers has given the trust options to determine the condition of the lower caisson. The best, it says, would be to remove the breakwater rocks in two spots adjacent to the lighthouse — assuming permission to do so can be obtained from the U.S. Army Corps of Engineers — and drill several core samples through the cast iron plates and into the cement inside, to determine the location and extent of any voids that may have been formed between the plates and the cement. That would cost $80,000.

A less expensive, but also less effective, option would be to create an opening in the caisson and attempt to insert an inspection camera for a visual inspection. This alternative would cost approximately $25,000.

“The initial estimates are just to determine the extent of the damage to the caisson,” said Thompson. “The engineers will then have to develop a plan to effect repairs and stop any further damage.”

The study estimates it will take $180,000 to make all of the recommended repairs to the lighthouse. However, that does not include the cost of removing and replacing rocks from around the lighthouse, or the amount needed to repair and reinforce the caisson itself. Total costs “could well exceed $300,000 to $500,000,” the report says.

Having to actually replace any of the lighthouse’s plates could be an expensive and difficult process, said Thompson, because few mills in the U.S. still produce cast iron sheets.

“Maintaining and preserving a lighthouse in a highly corrosive saltwater environment is not for the faint of heart,” Thompson said. “Corrosion is taking place every minute of every day. It never stops.

“The challenge for the Trust is to raise funds through grants and donations to take action now to stop any further deterioration,” Thompson said.

According to historical records, problems with the lower caisson are not new. The lighthouse’s flame, a single kerosene lamp, was first lit on May 24, 1897. Thanks to the original fifth-order Fresnel lens, that light could be seen for 14 miles, warning ships approaching the South Portland harbor. However, by 1912 the old lighthouse board was forced to place steel bands around the five cast iron-flanged plates that form the caisson construction. The bands were again repaired in 1929. The upper band is no longer effective and it is assumed by the engineers that the condition of the lower bands, hidden by the rip-rap and breakwater stones, is “poor.”

The trust says the structure is safe — good to know for the 3,500 people who tour it each year — and that it is not concerned about its short-term viability. According to the report, “There is currently no indication of structural instability.”

However, trustees are concerned about the cost to ensure that the lighthouse, said to be the only one of its type in the country accessible to visitors by land, stands for future generations to enjoy.

Grants from the Davis Family Foundation and the Morton-Kelly Charitable Trust funded the recent study, but that does not mean grants for repairs will be automatically forthcoming. After all, Thompson said, “There is a lot of competition out there,” for grant dollars.

“Our best hope is that someone will come along and write us a big check,” said Thompson. “It would be a shame to allow the deterioration to continue to the point where the lighthouse is no longer safe to open to the public.”

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