The rust stains on the gas connections were found to originate primarily 

 from the mild steel clamps used to secure the flexible tubing to the steel 

 nipples. No significant attack of the tubing, tubing clamp or nipples was 

 noted. No significant attack on the antenna support arms was noted although 

 voluminous loose flaky red rust was present in many areas of paint failure. 

 The attack under the rusted areas was uniform. 



The condition of the syntactic foam blocks of the foam tower is 

 illustrated in Figure 15. Although the coating at the identifying letter 

 had failed, the underlying material was unattacked. No signs of water' 

 absorption or deformation of the foam blocks of the foam tower, low 

 frequency antenna or gas generator support was noted. The main lifting 

 eye at the top of the foam tower, as shown in Figure 16, was covered with 

 a thin film of loose flaky red rust but no significant corrosion was noted 

 underneath the rust layer. 



Repa i r of Tower 



Echo tower was to be reemplaced if its condition permitted. As the 

 damage resulting from emplacement and retreival was minimal and the amount 

 of corrosion found did not preclude reemp lacement, the tower was repaired. 

 The four shock absorbers were replaced with similar units. However, the 

 tips on these units were screwed into place in contrast to the pressed-in 

 units originally used. These screwed-in tips were further secured by 

 welding and are shown in Figure 17. The universal joint was re I ubr icated . 

 The tower base, universal joint, main column and buoyancy sphere were 

 cleaned by an air powered high pressure water jet and recoated with a 

 copper oxide-pigmented rubber-based antifouling topcoat. The yellow enamel 

 identifying marks were reapplied after the antifouling coat had cured. 

 The condition of the buoyancy sphere after repair is shown in Figure 18. 

 The fasteners used to secure the cable conduit to the main column were 

 recoated as required with a rubber based sealing compound. Rusted areas 

 on the steering carriage and antenna support arms were cleaned and recoated 

 with a two coat, po I yami de-cured epoxy paint system. The gas generators 

 were replaced. The attacked areas on the antennas were carefully sanded 

 and cleaned before recoating with the same paint system. The gas con- 

 nections between the ends of the compliant tubes and the gas manifolds 

 were cleaned, the clamps and tubing replaced as necessary and recoated with 

 a two component sealing compound where any rust staining of the connections 

 was noted. Areas of paint failure on the foam tower were repaired using 

 the topcoat of the polyamide cured epoxy paint system. Identifying marks 

 were reapplied to the foam tower. The recoated foam tower is shown in 

 Figure 19. The main lifting eye was cleaned, and then recoated with the 

 two coat polyamide cured epoxy system. The tower was then considered to 

 be ready for reemp lacement. 



