Testing plays a very important role in the integration of underwater vehicles and technologies before delivery for operational use. Both European and FSU developers stress a bottoms up factory test approach that tests components, subsystems, and finally complete systems. European developers that the WTEC team visited employ test methods very similar to those used in the United States. Russia and Ukraine differ from the United States only in the sophistication of test equipment in use. In the West, simulation testing is often used as an overall final factory acceptance test. It couples environmental and mission simulation modules with system hardware and man in the loop to perform end-to-end functional acceptance tests. Simulation testing is most often performed dry, but can also be done in suitable wet tanks or pressure chambers, if available. Automated test equipment (ATE) is used extensively in the West, and provides a preprogrammed, computer-controlled capability for high volume test sequences such as life cycle testing and production testing of complicated electronic equipment. Simulation and automatic testing require more capable computer assets than are generally available to most developers in the FSU, hence, the lack of this kind of test activity was anticipated. One exception was at Krylov, where advanced automated test facilities were observed. In general, very capable test facilities are available in both Europe and the FSU for the type of applications and vehicles that are in use. Tables 7.3a and 7.3b summarize the test activities and facilities that were observed or described to the panel. Some of the more unique facilities are discussed in the following paragraphs.
In both the United Kingdom and France there are very capable physical and functional test facilities in use. Simulation laboratories and automated test equipment were observed (see Heriot-Watt University, LIFIA, and Marine Technology Directorate site reports in Appendices D and E); they are used to test systems and components for underwater vehicles.
Pressure chambers of various sizes and depth capabilities are available in Europe. The most impressive was found at Slingsby Engineering Ltd. Slingsby has a 3 m diameter horizontal chamber (see Figure 7.2) with a unique, half-cylinder support carriage that allows for entry of test articles nearly the size of the full diameter of the chamber. In this manner, the company can functionally test even its largest ROVs to depths of 7,500 feet. Large chambers capable of testing complete vehicles to full ocean depth (6,000 m or more) were not found, but may be available at other locations. Handouts at Rauma Oceanics in Finland listed a reasonably large (2.5 m diameter) chamber good to 7,500 m, but the team was not allowed to tour any of the company's facilities.
Test Facilities Observed or Available in Europe, Russia, and Ukraine (1)
Test Facilities Observed or Available in Europe, Russia, and Ukraine (2)
Figure 7.2. Pressure Test Facility at Slingsby
The emphasis on testing in the FSU has led to a plethora of very capable test facilities for both ocean research and development test of underwater vehicles in these two countries. The most unique were clearly found at Krylov Shipbuilding Institute in St. Petersburg (see Krylov Shipbuilding Institute site report in Appendix B). Krylov is Russia's equivalent to the David Taylor Research Center (DTRC) at Carderock, Maryland. In fact, Krylov's test facilities are more extensive and in many ways superior to DTRC's. The very long tow tank (1.4 km) and massive pressure test chambers are truly world class. Krylov's largest chamber is over 3 m in diameter and capable of testing to 1,000 atmospheres (14,700 psi or > 33,000 ft). The slightly smaller chamber (1.8 m diameter) is rated at 1,500 atmospheres, which is well beyond full ocean depth. Krylov is unique in the FSU in that it has computer controlled test facilities. The structural test facility (see Figure 7.3) can life cycle test full-sized ship panels by hydraulically applying simulated loads in numerous positions at temperatures down to -110°C and measuring up to 3,000 data points to monitor fatigue and cracking.
Figure 7.3. Structural Facility at Krylov
Other test facilities observed in Russia and Ukraine, while not as impressive as those at Krylov, were still very capable and have been used extensively in developing advanced marine technologies. As summarized in Tables 7.3a and 7.3b, acoustic, hydrodynamic, and pressure test facilities were found at many institutes and were adequate for both research and component development. However, the only facility that appeared to be large enough to test a complete manned submersible hull was the facility at Krylov. Computer controls, automated test equipment, and modern data acquisition equipment were not observed at any of the other test facilities.
Integrated test of completed vehicles does not appear to be emphasized in Russia or Ukraine as it is in the West. This is probably due to the less complicated vehicles that have been developed. Simple manned vehicles, without high-tech controls and subsystems, translate into simple test equipment and approaches.