METAR Cable Management Systems | Page 46

METAR LADDER METAR LADDER Load-Deflection Tables 2.4.3 METAR Equal & Unequal Tees Speedway Equal & Unequal Tees (300mm Radius) METAR Equal & Unequal Tees (450mm Radius & Above) 600mm 300mm 300mm Radius 2/3R 450mm Radius & Above 600mm 300mm 2/3R 600mm 2/3R When correctly mounted and secured, cable ladder can be considered to be a ‘conti nuous beam’. This implies that the cable ladder run is regularly supported and that the cable ladders at the extremities of the run are firmly anchored. The following tables are used to calculate the safe working load and have been verified by testing in accordance to BS EN 61537 .The load bearing capacity of a cable ladder is limited by the lesser of the maximum allowable stress induced in the side members and rungs or the maximum deflection acceptable in the same members. The maximum allowable stress is usually limited by the materials lower yield stress; this gives a safety factor of 1.7 against the ultimate tensile strength. Maximum deflection, (in the absence of a particular customer need) is not allowed to exceed 1/360th of the distance between supports (span) longitudinally or 1/200th of the rung length (cable ladder width) transversely. 300mm For equal and unequal tees with radii of 300mm, supports should be located within 300mm of the tee on each branch in the cable ladder run. For equal and unequal tees with radii of 450mm and above, supports should be located within 600mm of the tee on each branch in the cable ladder run. Intermediate supports should be placed at approximately 2/3 of the radius (R) on each branch of the tee as shown. Loading Data - Vantrunk Extreme Steel Hot Dip Galvnaized Finish The data given in the tables is for METAR cable ladder installed as a continuous beam and allows for the weight of the ladder itself. The safe working load values represent a uniformly distributed load and a factor of 1.7 as recommended in the cable ladder European standard. This information is given for guidance only and larger safety factors can be used depending on the installation. The METAR Cable Ladder system, components and accessories have been tested to BS EN ISO 61537. Further details are can be provided by our Design Team. Loading Data - 1.4404 Stainless Steel (316 Marine Grade) Span & Safe Working Load kg/m Ladder Type Width W mm 2m 2.5m 3m 3.5m 4m 4.5m 5m 5.5m 6m MT4/SL/150/G 150 542 346 239 175 133 - - - MT4/SL/300/G 2.4.4 METAR Intersection Although unusual, there may be occasions when it is difficult or indeed impossible to anchor the cable ladder securely in position. Under these circumstances the ladder is ‘simply supported’ and its load bearing ability is substantially reduced. As a rough guide maximum loads should be limited to two thirds of those shown in the loading tables and increased deflection values should be accepted for each span. 300 542 345 238 174 132 - - - Span & Safe Working Load kg/m Ladder Type Width W mm 2m 2.5m 3m 3.5m 4m 4.5m 5m 5.5m - MT4/SL/150/SS 150 473 301 208 152 115 - - - - - MT4/SL/300/SS 300 473 301 208 151 115 - - - - 6m MT4/SL/450/G METAR Intersection (450mm Radius & Above) 450 541 345 238 173 132 - - - - MT4/SL/450/SS 450 472 300 207 151 114 - - - - MT4/SL/600/G 600 470 344 237 173 131 - - - - MT4/SL/600/SS 600 445 300 207 150 114 - - - - 750 369 343 236 171 130 - - - - MT4/SL/750/SS 750 282 282 206 150 113 - - - - MT4/SL/900/G 900 254 254 235 171 129 - - - - MT4/SL/900/SS 900 194 194 194 149 113 - - - - MT4/SL/1000/G 1000 184 184 184 170 128 - - - - MT4/SL/1000/SS 1000 140 140 140 140 112 - - - - 150 - - 491 359 274 215 173 - - MT5/SL/150/SS 150 - - 429 314 239 188 152 - - MT5/SL/300/G 600mm MT4/SL/750/G MT5/SL/150/G METAR Intersection (300mm Radius) 300 - - 491 359 273 214 172 - - MT5/SL/300/SS 300 - - 429 313 239 188 151 - - MT5/SL/450/G 300mm Radius 300mm 450mm Radius & Above 450 - - 490 358 273 214 172 - - MT5/SL/450/SS 450 - - 428 313 238 187 150 - - MT5/SL/600/G 600 - - 490 358 272 213 171 - - MT5/SL/600/SS 600 - - 427 312 237 186 149 - - MT5/SL/750/G 750 - - 367 356 271 212 170 - - MT5/SL/750/SS 750 - - 350 312 238 186 150 - - MT5/SL/900/G 900 - - 251 251 251 211 169 - - MT5/SL/900/SS 900 - - 240 240 237 186 149 - - MT5/SL/1000/G 1000 - - 181 181 181 181 168 - - MT6/SL/150/G 2/3R 150 - - - - 357 280 226 185 155 MT5/SL/1000/0S 1050 - - 174 174 174 174 149 - - MT6/SL/300/SS - - - - 311 244 196 161 134 300 MT6/SL/300/G 300mm 300mm 300mm 600mm 2/3R 600mm 300 - - - - 356 280 225 185 154 MT6/SL/450/SS 450 - - - - 310 243 196 160 134 MT6/SL/450/G 2/3R 450 - - - - 355 279 224 184 153 MT6/SL/600/SS 600 - - - - 309 243 195 160 133 MT6/SL/600/G 600 - - - - 354 278 223 183 152 MT6/SL/750/SS 750 - - - - 308 242 194 159 132 MT6/SL/750/G 2/3R 750 - - - - 354 277 223 182 152 MT6/SL/900/SS 900 - - - - 308 241 194 158 131 MT6/SL/900/G 600mm For crosses with radii of 300mm, supports should be located within 300mm of the cross on each branch in the cable ladder run. 900 - - - - 251 251 222 182 151 MT6/SL/1000/SS 1000 - - - - 237 237 193 158 131 MT6/SL/1000/G 1000 - - - - 181 181 181 181 150 MT6/SL3/1000/G 1000 - - - - 171 171 171 157 130 For crosses with radii of 450mm and above, supports should be located within 600mm of the cross on each branch in the cable ladder run. Intermediate supports should be placed at approximately 2/3 of the radius (R) on each branch of the cross as shown. 41 42