Look Down, Too

[Music] today when we think of research in connection with our defense efforts the tendency is to look up up at aircraft and missile weapon research up at outer space research in military applications these spectacular items have been given the Lion Share of attention and publicity in recent years however we must continue to look down to look down at the oceans of this world on and under which naval ships operate our Navy is unquestionably a vital part of our defense system carrying a wide assortment of aircraft and missile Hardware to any point within Striking Distance of a potential enemy but suppose our submarine is immobile ized by an enemy underwater weapon or our cargo ship loaded with equipment for a landbased missile installation sustains a hit which results in Sinking and loss of that vital cargo naturally the value of any ship depends on its ability to withstand such attacks and complete its mission an organization devoted to research in the effects of and protection against such attacks is the underwater explosions research division or UE as it's usually referred to although UE is part of the Navy's David Taylor model Basin of cter rock Maryland near Washington DC U itself is located in this building at the Norfolk Naval Shipyard in Portsmouth Virginia abundant Recreation and historical areas are within a few miles of U Personnel at UE consists of Engineers physicists mathematicians and Naval architects who plan and direct underwater explosion experiments and are supported in the effort by test technicians and Artisans this film will show you some highlights of research accomplished by UE for the Improvement and design for strengthening structures and equipment in both surface ships and submarines tests using underwater explosions with full scale ships or models will be demonstrated in the following order first to show what happens in the water at the time of an underwater explosion second the response of Submarine hulls third the machinery and equipment on submarines fourth the machinery and equipment on Surface ships fifth Hull or structural response of surface ships before showing these five categories of Investigation let's look at the floating facility from which most of the tests are conducted the underwater explosions barge or ue1 and sometimes referred to as the Lulu built in 1942 it has since been changed and improved considerably it's the only one of its type in the Navy and its usual crew is all civilian since it has no propulsion machinery it has to be towed wherever it goes but once there it is self-sufficient with its insides crammed with generators pumps compressors and so forth in addition to its own crane for light loads it is equipped with hoists to handle heavy scale models like the submarine model for transport to a remote test site on the test site heavy models are often held out of the water to facilitate repairs or installations during during a series of tests several times the ue1 itself has been used as a test vehicle with a large model welded directly to its Stern naturally the ue1 receives quite a bang out of a test of this sort and equipment aboard has to be protected this entire room is the main recording Center installed permanently on the ueb about midships it is suspended on Springs and shock absorbers for protection to the delicate electronic equipment used in recording the strains velocities and other effects of the explosive loading to the model or equipment under test the ue1 also has complete birthing and messing facilities for all the test Personnel on a long trip to a farway test site before any Target is tested it is instrumented with an assortment of Strang looking gauges developed by the instrumentation engineers at U these gauges record the response of both Hull and Equipment the gauges are connected to terminal boards on the target itself and then through heavy cables leading from the target to the ue1 and finally to the main recording Center on the ue1 an auxiliary recording center mounted in a trailer and hoisted aboard is also used on large tests requiring additional and backup recording manually operated high-speed still and movie cameras record the exterior effects and automatically operated high-speed cameras record the interior response sometimes a model will be flooded with water from leaks caused by the explosion and cameras have to be protected with watertight boxes they are always shock mounted for protection against mechanical damage now let's see what an underwater explosion is really like most of you have seen the surface effects of an underwater explosion here is an actual underwater explosion of a small charge in a test tank notice the pulsing action of the gas bubble this surface view shows first the spray Dome caused by the initial shock wave then a column or plume of water is sent upward due to the bubble pulsing below the surface the size of the charge and its depth govern these effects the testing of submarines has been carried on at ard for some time a tribute to the engineering knowhow plus the versatility of the ue1 is this remote control operation of a full-size Submarine by a complicated system of valves in compressed air furnished by the ue1 the submarine is submerged to a predetermined dep the explosive charge is fired from the control center on the ue1 and the submarine is brought to the surface so that results can be evaluated and preparations made for the next test here is a test of a full scale model submarine section Machinery is simulated with weights mounted in the proper location note the response of the hull plate the watertight envelope of a submarine which must be designed to withstand depth charge attack time is expanded considerably here due to the high framing rate of the camera actually this action took place in less than 10 milliseconds with the increased range and deeper diving requirements of our new submarines come problems in stronger pressure Hull and internal equipment designs a full-scale submarine section was designed and built by U this vehicle operated remotely as you see here has been used for a number of tests for both Hull and Equipment study vital items aboard our submarines have to be designed to withstand severe shock from underwater explosion attack and then proof tested this is especially so with valves and other penetrations of the hull which can be open to the Sea this is what may happen under severe shock loading to the submarine after improvements the valve held up under even more severe shock during a later test score one for research other essential equipment such as elect panels and navigation devices need investigations for survival UE designs constructs and tests many types of scale ship models actual pieces of Machinery are tested and evaluated as single units on a floating platform form designed and maintained by U this means of testing affords an evaluation of equipments furnished by manufacturers prior to their acceptance for installation aboard operating ships of our Navy since the platform itself is built rugged enough to withstand test after test without damage it has proven to be a very economical as well as realistic method of testing heavy shipboard items here is a turbo generator test on the floating shock platform the turbine was running at normal operating speed during the test series notice the movement of the heavy Foundation at the top of the screen here is a repeat view of that test in this view note the violent motion of the flex plate of the turban that bright flash of light is an ordinary photo flash bulb which indicates zero or detonation time a diesel engine test watch the exhaust line break at the flange connection let's look at that one again also another Diesel with a flexible shaft coupling and noise isolation m and a different view of that same test various Hall designs are tested by U several capital ship designs have been strengthened as a result of preliminary investigations and changes recommended by U the torpedo Protection Systems of our newest aircraft carriers have been studied using a scale section which you see here attached to the ue1 even though the interior damage shown in following scenes looks pretty serious the innermost and vital compartments remained watertight e landing craft of many types have been tested for resistance to mine explosions obsolete ships destined for the scrap Heap are used as test Vehicles whenever feasible this old Destroyer has served her country well first as a fighting ship during World War II and then as a target for several underwater explosion tests many new types of equipment were mounted for this test e now that the testing is over we come to the real reason for it all the evaluation and dissin a of all the information we have gained parts of this film you are seeing have been used in technical film reports which have proven valuable in understanding where and how equipment and structural failures occur a more complete report is published primarily for use by Design Engineers Naval Architects and others concerned with the Improvement of ships a survey is made throughout the ship or model and all damage is listed photographs of this damage are made for use in the report gauge records are played back from magnetic tape on a light sensitive paper which gives a visual record the data reduction section converts this visual record into digital tabulations and on punched cards then these punched cards are fed into a reader and automatically plotted to enlarged or compressed uniform scales for ease of analysis project Engineers correlate all this information they develop and apply theories to interpret EXP experimental data in terms of basic concept then compile a report of their findings and the ultimate goal the printed report is distributed to defense activities and contractors whose need to know will enable them to use the information for stronger designs in order to keep our Navy equipped with the very [Music] best