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Design of TSQ-81

Michael Ruotolo


The TSQ-81 was designed and built by the Reeves Instrument Corporation, located in Garden City, Long Island, New York. The radar was a reconfigured version of the MSQ-77 Bomb Scoring Radar System. At the time I was a Mechanical Engineering Section Manager at Reeves. Dr. Timothy N. Castle, in his book, has documented in some detail the efforts at Reeves. I will attempt to add some additional details of the Reeves effort.

My first introduction to the classified TSQ-81 program was when, at Reeves, USAF personnel, I believe led by a Colonel, disclosed that the MSQ-77 Bomb Scoring System was to be reconfigured into a tactical system. As I recall he was quite excited that a SAC Bomb Scoring system, which was designed to track a simulated bomb, could be used to accurately drop actual bombs. The radar system was to be a classified top priority accelerated program. The bulk of the effort was to be a mechanical engineering task, since it involved turning a van mounted unit into a portable helicopter transportable unit, which could be assembled and reassembled a number of times. We were informed that it was to be located at several locations in Southeast Asia and that its main task was to direct strategic and possibly tactical bombing runs. We worked 24 hours a day, 7 days a week in three 9-to10 hour shifts to design and build a reconfigured system. Shifts overlapped by one to two hours to insure continuity of information from one shift to another. As Dr. Castle notes in his book, the first prototype was delivered in one month.

It was decided to use an off the shelf steel prefab building configuration to expedite the design. These buildings were designed to be on concrete slabs, which was not practical for the intended application. It was decided to fabricate the base of bolted steel wide flange beams. It was to these beams that the building was fastened to. The beams themselves were anchored to the ground with guy cables. The actual floor consisted of sheet steel in a top hat configuration, which in turn sat inside the wide flange beams. This was covered with plywood to complete the floor. The top hat floor sections could be nested into one another during shipping to minimize size. The antenna was much too heavy to be mounted on the building roof. A separate steel structure straddled the building and provided a mounting platform for the antenna. A rubber boot was used to provide a weather tight seal between the building and the antenna. The photograph taken at Reeves shows some of the building detail at this location. I believe the building is the first unit, serial number 7. The photograph shows three Reeves technicians, hoisting the antenna azimuth drive. It was raining that day and I am the fellow in the light colored raincoat, with his back to the camera.

The photograph also shows the use of the hoist that I had selected, a commercially available unit. Because of the time constraint, we tried to design around readily available items. I had become increasingly involved in the day-to-day design and fabrication after my mechanical engineering project leader was on the verge of a nervous breakdown. He requested to be reassigned, and much of his workload on the project fell to me. During the course of the project we were informed that one of the units was to be installed on a mountaintop in Laos. There are numerous incidents, which I vividly recall, such as the photographs of the mountaintop and told how the area had been cleared with explosives. I was told it eventually was cleared with a small bobcat like bulldozer that was helicopter lifted to the mountaintop. At that time we had no idea what the actual mountain top site looked like. We requested site dimensions and photographs of the location. This is perhaps when Lt. Col. Seitzberg was directed to obtain the information. The effort to prepare the mountaintop could not provide a large enough flat area for the system, and we were told that it had to be on several levels. The surface, we were told was solid rock. The wide flange beams, supporting the building, were anchored with guy wires to the ground. Drills were supplied to prepare the rock surface for the guy wire anchors. We were also told because of its sensitive location that all markings and nameplates that could identify the equipment as American had to be removed. In some cases grinders were used to remove the markings.

The TSQ-77 had to be broken down into loads small enough so that a CH-47 Chinook helicopter could airlift the load at the Lima Site 85 altitude. The system was transported in plywood boxes. The boxes themselves could to be broken down into storable panels. Some of the boxes were transported in the Chinook; others had to be slung underneath. In order to insure that every box could be airlifted, we requested that a Chinook helicopter be brought to Reeves so that we could conduct a dry run. I was involved in that, and recall fastening the lifting cables to the top of a box. It was not a simple task with the rotor blades downwash and the gravel and dust swirling around. We tried to design the system such that all the boxes could fit into the Chinook, but that was not possible.

During the design and fabrication cycle we were training both Reeves field engineers and USAF personnel. When the systems were deployed we did get feedback for design improvements. It was a very intense program, and one I will always remember. My entire engineering career, from 1956 until 1997, was spent designing military equipment. I had served in the Army, but I had never seen combat; many of my designs unfortunately did.


Michael Ruotolo

The history of the building of the Lima Site 85 scale model is quite interesting. I had worked on the design of both the MSQ-77 and the TSQ-81 as a mechanical engineer at the Reeves Instrument Corporation and was familiar with the history of the TSQ-77 sites. One evening I just caught the ending of a book review TV show where Dr. Timothy Castle was being interviewed. I realized that he had written a book which talked about a Radar System I had helped design. Unfortunately I did not get his name or the book’s name. I mentioned it to my two sons; I tried, but could not locate the book, since I did not know the title or author. My younger son, Fred, an attorney, had been a 1st Lt. in an M-109 Artillery Battery, and has always been interested in military history. He came across the book, Lima Site 85, while browsing at a bookstore and immediately realized that it was the TSQ-81 story. Both my sons read the book; my older son said he would love to build an HO scale model of the site. My older son, Michael, is a CPA; he is presently the Director of Finance of a magazine, and as an avocation an accomplished model builder.

Michael asked if I could obtain information on Lima Site 85. I contacted Dr. Castle and he put me in touch with you and your website. Based on the photos from the website and some information I gave him, he built the model. The model is scratch built using material normally used on HO scale train models. Based on some dimensions I gave him, he extrapolated the remaining details. It took him quite a long time to research information and to find some of the materials he used. It took him a much longer time to build the actual model. The model is built using sheet plastic, finding the right thickness to match the scale was a recurrent problem. He presented the model to me this father’s day and took the digital photos of the model you see.

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