Masonry Magazine March 1979 Page. 26
PINE STREET INN TOWER
Because of the thickness of the walls (over 3 feet at their base) the stresses in them were thankfully low.
Tracings were then made of various horizontal sections of the tower from actual field measurements. These tracings were superimposed over each other in order to determine the relationship between the walls, corbels and piers. This process revealed that the walls at the corbels at the low roof were over 4 feet thick, which meant that the structure supporting them was perhaps sounder than it seemed from the outside.
Study of the field notes, photos and the scale drawings indicated one important fact. The large cracks in the exterior did not appear on the inside, indicating that the damage might extend only as far as the exterior veneer. The forces of nature were peeling off the exterior skin of the tower as one peels off the skin of an onion. If this was the cause of the damage, the repair of the tower would consist mainly of replacing the damaged brick and sealing the walls to prevent water from entering them again.
To keep the tower's arches intact while the old mortar was being cleaned out from behind the brick, screw jacks were placed horizontally between the scaffolding and wood blocking placed across the face of the arches. Pressure was increased as the loose mortar was removed. After this process, the entire arch was pushed back to its original position and a header course placed along the top to tie the veneer to the rest of the wall.
Contract Documents
The repair of the tower could be bid as 1) a separate entity or 2) it could be part of a total masonry sub-bid. The advantage of the first was that contractors who specialize in this type of work could bid it. However, the possibility of finding three qualified contractors appeared slight. Also, the bidders would have to apply a factor to cover unforeseen problems. Because of these concerns the second method was chosen. The total estimated masonry sub-bid was over $200,000, and the complex tower repair would only constitute one-third of that. A masonry sub-bid of that size as well as the fact that two-thirds of the work would be straightforward would increase the possibility of getting enough contractors to bid the work.
The scope of the repair work had to be clearly indicated in the contract documents, and many approaches were studied. One method of applying pictures to the originals was considered. The problem with this method was that not every part of the tower could be clearly photographed. The method finally adopted was to draw a plan of each of the five levels of the tower and indicate the scope of work on each plan. In addition, a comprehensive document for the mason to follow in repairing the brickwork was needed. As much information as possible was condensed onto a single sheet in the form of a series of tower repair notes.
A drawing showing the entire height of the tower on every side, interior and exterior was made. All repair work was shown on these drawings by circling the areas to be repaired and keying the required repairs to a repair schedule.
Repair of the Tower
The contract documents were completed in April of 1976. Before bidding could start the various city and state agencies had to review them. When a bid date had not been set by September, the Boston Redevelopment Authority, which then owned the building, was informed that the tower was structurally unstable and repair work had to be done before winter. If water penetrated the brick and froze, large sections of brick could fall off the tower and injure passersby. With the Boston Redevelopment Authority's blessing, a brief specification and a couple of drawings were developed to remove the hazardous top of the tower.
Bids were solicited from several contractors that specialized in chimney building and repair, and work proceeded immediately. The piers on top of the parapet wall were so loose that a crane was able to lift them up in one piece and lower them to the ground. The stone copings and the yellow brick were stacked up inside the building and used later to rebuild the top of the tower.
At this point, the Boston Redevelopment Authority began receiving protest calls as the men dismantled the parapet. The BRA assured the public that the tower would be restored to its original appearance at a later date.
In the Spring of 1977, Coronis Construction Co. of Winchester, Massachusetts, came in as the low bidder for the project. After the scaffolding had been set up around the tower, the contractor began replacing the broken brick on the corners. The exterior veneer was removed and the back-up brick examined for cracks. When no cracks were found, the corners were rebuilt using salvaged brick from the site.
Work was then begun on the top portion of the tower. The first step in rebuilding it was to repair all the loose brick in the small corbels and arches. The exterior wythes of the arches were not tied back to the rest of the tower, and the brick were being held in place by gravity alone. Several ways to tie these arches back were discussed with the masons working on the tower; the method finally decided upon indicated their exceptional skill and ingenuity.
Using brick and mortar to match the original 1892 materials, masons rebuilt the piers at the top of the tower to their original size and shape on top of the new concrete coping.