three FRPE units, one enameled-steel tub, and one cast-iron tub. The table is self-explanatory and is presented for information only. Table 2.2-3 is a compilation of various dimensions of all tubs used in these tests and is presented for information only. An examination of table 2.2-1 shows that all tubs tested had center deflections of less than 0.125 in, and had residual deflections 10 min after load removal of less than 0.003 in. (3) Rationale for Test Selection The basic concepts of the proposed revision of the Commercial Standard were preserved in the recommended test; however, several modifications were incorporated. The first was to enlarge the distribution pad from a 3-in-diam circular area to a 5-10-in rectangular area. This change was made to more closely simulate the area covered by a person standing in a bathtub. The larger area also permits the use of dead weights for load application. The test as described in the proposed revision of CS 221-59 made no provision for correcting for settlement of the tub in the frame when the load was applied. The present test procedure considers the possibility of error from this source and corrects for it through use of three gages rather than one. The length of time for the applied load to remain on the bathtub was increased to 5 min. to coincide more nearly with service use. d. Comments on Performance Requirements (1) Suggested Format for a Performance Level The bathtub shall show no damage to either the visible or non visible surfaces from the testing. In addition, the center deflection 5 min after the load is applied shall not be greater than in nor shall the residual center deflection 10 min TABLE 2.2-2. Static load tests to destruction (5- × 10-in Specimen No. and material PB-4 FRPE PC-1 FRPE PD-1 FRPE SA-4 Steel CIA-4 Cast Iron 5, 100 At 2,550 lb, center reinforcing member broken. At 3,630 lb, head-end reinforcing member broken. At 4,090 lb, drain-end reinforcing member broken. Transverse cracking of fixture across sump at maximum load. 18,000 Audible cracking of reinforcing member began at 2,350 lb. No visible damage to coating. Reinforcing under sump splintered. Test discontinued at 8,000 lb.1 5, 500 At 3,550 lb, spalling around rim. Primary structural failure from buckling of flange at head end. Spalling of coating in bottom of sump near center and permanent set of about 1 in at point of application of load. 6,900 Crack in fixture along longitudinal center line of sump about one-half the length of the bottom at maximum load. Loading discontinued, because 8,000-lb load caused sump bottom to bear on reinforcing structure. (2) Rationale for Suggested Format There are two reasons for limiting the center deflection of the bathtub. The first is to insure that the bath or shower water will drain completely from the tub even though the bather remains in the tub. The second reason is that large deflections may instill a feeling of insecurity in many users. The reason for limiting the residual deflection after load removal is to provide some assurance against accumulative permanent set from repeated loadings, which might eventually make the fixture unusable. 2.3. Rim Load (Bathtub) (S102A) a. Purpose and Scope The purpose of this test is to determine if a bathtub will withstand a 300-lb. load applied at the center of the front rim without damage. The service load simulated is that of a person sitting or standing on the bathtub rim. b. Recommended Test Method (1) Equipment Required for Test 1. The load-application method shall be as specified in section 2.2.b (1). 2. The load-distribution pad shall be as specified in section 2.2.b (1) except that the area of the pad shall be 7- X 7-in. (2) Preparation of the Test Specimen The bathtub shall be mounted and supported for test as specified in section 2.2.b (2). The inside surfaces of the tub shall be inspected in accordance with the procedure described in section 2.8. (3) Test Procedure Maintain the temperature of the testing laboratory and bathtub at 755 °F. Apply the test load through the distribution pad at the center of the front rim. Apply the center of the load to the center of the pad, and leave in place for 5 min. After removal of the load, inspect the finished surfaces of the bathtub for damage. (4) Information to be Reported Include the following in the test report: 1. Specimen identification; 2. Method of supporting and fastening speci- 3. Description of test frame; c. Test Results and Discussion (1) Discussion of Existing Methods Commercial Standard CS 221-59 [2] requires that a load of 300 lb be placed on the deck corners and at the mid-point of the rolled-over edge of the bathtub. The load which is applied through a pad of suitable soft material is left in position for 1 to 10 min. The loaded area is 7 in by the width of the rim. No permanent deformation nor any cracking or crazing is allowed. The proposed revision of CS 221-59 [1] is essentially the same except that the no-permanent-deformation requirement was removed. The proposed revision also specified that the mid-point and one end of the rim should be loaded through a 3-in round pad. No provision was made for loading other areas. (2) Test Development The basic features of the proposed revision of CS 221-59 were considered to be satisfactory. During test development, the 300-lb test load was applied at various positions about the rims of the tubs. Deflection measurements of the rim as well as lateral movements of the front apron were made. Table 2.3-1 describes some of the lateral-movement measurements made on the various tubs. Since deflections of the rim and lateral movements of the apron due to an applied load are partly dependent on the restraints imposed on the tub as a result of installation, none of the measurements was considered significant. The data presented in table 2.3-1 are for information only and are not intended for use in evaluating the tubs. No surface damage attributable to the 300-lb test load was observed on any of the tubs tested. (3) Rationale for Test Selection The recommended test procedure is similar to that outlined in CS 221-59 [2], with one exception. The single test area, chosen as the center of the front rim, subjects the tub to the greatest possible flexural load and therefore is the most desirable location for applying the test load. The rim load is recommended as simulating the service load from a heavy person sitting or standing on the rim. The test is needed to evaluate the resistance to surface damage that possibly could result from high flexural stresses. d. Comments on Performance Requirements (1) Suggested Format for a Performance Level Surface finish damage that can be attributed to the test shall not be allowed. The inspection procedure prescribed in section 2.8 shall be used for evaluation of damage. (2) Rationale for Suggested Format No limit on deflection or lateral movement is included in the suggested format since the structural rigity of the tub can be determined by performance requirements for the static load test (sec. 2.2). In addition, lateral movement and resultant forces in service are affected by the degree of restraint offered by the method of installation, both of which may vary widely. The 300-lb load recommended approximates the weight of a very large person. It seems reasonable to expect a bathtub to withstand a service loading of this magnitude without surface damage. 2.4. Concentrated Dynamic Load (Bathtub) (S103) a. Purpose and Scope The purpose of this test is to determine if the bathtub will withstand, without visible damage, an impact load simulating a person falling or jumping into a bathtub. b. Recommended Test Method (1) Apparatus The falling-body test load shall consist of lead shot in a leather bag. The total weight of the falling body shall be 150 lb (±1 lb). The bag shall be cylindrical, 9 in in diameter by about 18 in high. The leather shall be similar to that described in Federal Specification KK-L201e for lacing leather. It shall be made from at least two pieces of leather so that the bottom, striking, surface will be seamless. A method for closing the top opening of the bag shall be provided to prevent loss of lead shot. NOTE: As the bursting force is high, the sewing of the seams is critical. The size of thread used should be as large as practical to reduce the tendency of the thread to cut the leather. The method of hanging and releasing the bag shall be such that the center of the point of impact in the tub can be estimated to within 0.5 in and the height-of-drop can be adjusted to within 0.1 in. NOTE: The buckle from an automotive safety seat belt is satisfactory for a release mechanism. (2) Preparation of Test Specimen The bathtub shall be mounted and prepared for test as specified in section 2.2 The center of the sump shall be determined as in paragraph 2.2 b(3), and marked. (3) Test Procedure Maintain the temperature of the testing laboratory and bathtub at 75±5 °F. Drop the bag successively from heights of 5, 10, and 15 in, measured vertically from the center of the bottom surface of the bag to the point marked as the center of the sump. Make one drop at each height. Make certain that the center of the bag strikes within 0.5 in of the center of the sump. After the final 15-in drop, inspect the finished surface of the bathtub for defects in accordance with section 2.8. (4) Information to be Reported Include the following in the test report: 1. Specimen identification; 2. Method of supporting and fastening speci- 3. Description of test frame; c. Test Results and Discussion (1) Test Development A review of the literature revealed no existing standard test method that would produce the required conditions. Therefore, a simple falling-body test was developed to simulate the type of dynamic loading that might occur in service. A variety of containers, weights, support conditions, shockabsorbing pads, and heights-of-drop was tried prior to selection of the recommended dynamic test. Metal containers proved to be too difficult to control after impact. Sand-filled bags were too bulky and also difficult to control. Lead shot in canvas bags burst the canvas when dropped. Finally a leather bag was obtained which would withstand the force from the impact. Initially a 300-lb falling body was used. However, this was found to produce severe damage to some of the bathtubs except at unrealistically small heights-of-drop. The 300-lb test was abandoned as unrealistic, as field information indicated very little or no damage from service-inflicted loads of this type. Electronic instrumentation was devised to record the duration of impact and also the deflec tions. However, this was deemed too refined, costly, and time-consuming for the information obtained. The results of the development work indicated that a weight of 150 lbs in a supple leather bag dropped in increments of 6 in or less should constitute an adequate test. A relatively simple method was devised to measure deflections to 0.01 in by supporting a 6-in scale in a friction-clamping device. The scale was put into contact with the underside of the bottom of the tub prior to application of the load and the initial reading made. The deflection device had to be reset prior to each drop. As for the concentrated static-load tests (sec. 2.2), three deflection devices were used so that the observed center deflections could be corrected for tub and support movement. The relationships between heights-of-drop and deflections are shown in figure 2.4-1. Each pair of curves represents the maximum and minimum observed values for each type of bathtub tested. These data are presented for information only and are not intended for use in evaluating the dynamic properties of the various units. However, they do illustrate a reason for not including deflection as a performance requirement. For example, for a 24-in drop, the center deflection for the cast-iron tubs was between 0.1 and 0.2 in, but, for the FRPE tubs, the deflections ranged from about 0.4 to 0.75 in. It does not seem to be practical to use a limiting deflection as a performance requirement because of the wide variations in test results between materials and specimens. The data presented in table 2.4-1 show that damage to one steel tub was observed after an 18in drop. It should be noted that damage was observed only for the steel tubs. As the tubs were tested in height-of-drop increments of 6 in, it is not known if the observed damage would have occurred had the weight been dropped once only from a height of 18 or 24 in. Originally there had been some thought that, in lieu of a dynamic test, a heavier, static concentrated loading might be used. However, the data shown in figure 2.4-2 indicate that, if only deflections are considered, the relationship between the two types of tests is rather obscure for heights-ofdrop above 12 in. Furthermore, if the static load corresponding to the first-observed damage reported in table 2.2-2 for the destruction tests is considered, it will be noted that the damage occurred at 3550 lbs for the steel tub. This static load is well above the eqiuvalent static load indicated in figure 2.4-2 for the 18- or 24-in drop which produced damage in the dynamic test. (2) Rationale for Test Selection The recommended test was selected because it represents qualitatively the type of dynamic loading which might result from a person falling in, or jumping into, a bathtub. d. Comments on Performance Requirements (1) Suggested Format for a Performance Level The bathtub shall withstand without damage the test conditions specified in paragraph 2.4b(3) when the 150-lb weight is dropped from a height of in. Damage shall be construed as the appearance of any surface defects in the bathtub, visible damage to the reinforcing structure, or other deterioration of structural properties as a result of testing. (2) Rationale for Suggested Format It is believed that the following information might be helpful in arriving at a realistic performance level: 1. Field information (Appendix B) was obtained that showed a negligible incidence of damage to pressed-steel bathtubs from falls. Since some falls did occur, it can be inferred that the present tub designs are sufficiently strong to withstand this service condition. The pressed-steel tubs that were tested showed no damage at heights-ofdrop of 12 in or less, and only one showed damage at 18 in. 2. A person falling in a tub would normally strike the tub bottom near the end opposite the drain, where the tub has enhanced structural stability rather than near the center, where structural stability is near a minimum. Thus, a per HEIGHT OF DROP, IN. 24 O FRPE O STEEL ▲ IRON FIGURE 2.4-2. Correlation between height of drop in dynamic test and load in static destructive test. formance requirement based on impact at the center would be more severe than if based on impact near one end. Also, the leather bag filled with lead shot is probably more rigid than the human body and, for this reason, could produce more stress in the fixture at the instant of impact. Thus a given height of fall of the 150-lb test weight would simulate a greater height of fall for a 150-lb person. The data in table 2.4-1 show failures in steel tubs at heights-of-drop of 18 and 24 in, but no damage was observed at 12 in. 3. The use of successive heights-of-drop (5-, 10-, and 15-in) in the recommended test is believed to be desirable since there is a lack of information on |