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WTC North Tower collapse data



I've attached position v. time data from a CNN video of the collapse of WTC
North Tower cut from an Excel spreadsheet. The columns are 1) time from
beginning of video clip in seconds, 2) horizontal pixel, 3) vertical pixel,
4) horizontal position in feet (pardon the English units), 5) vertical
position in feet, and 6) the vertical position in feet (adjusted to account
for changes in the tracked object).

At 1.9135 s, 3.6592 s, 4.2635 s, I had to switch object to track, because
the first either left the frame or was obscured by dust. The pixel
positions of the old and new objects at that time are indicated. I
initially tracked one top corner of the tower, then points on the antenna mast.

The first two rows indicate data to determine the scale. I chose two
points with the same elevation at the corners of the tower on the side
facing the camera. The tower is rotated slightly about the vertical, but
not by much. The 9/12/2001 edition of the St. Louis Post-Dispatch lists
the sides of the square towers as "approximately 208 ft." The "scale" is
in feet/pixel.

Column 5 values at 2.35 s, 3.29 s, 3.3235 s, and 4.5321 s were padded with
zeroes just to make the columns in this message line up properly.

The video runs for about a second before the tower begins collapsing, but
there is still about 4 seconds of data here.

The Excel best fit 2nd degree polynomial for the adjusted vertical position
v. time after 1 s is

y = -10.811x2 + 10.691x + 0.0264 with R2 = 0.9978

This data may be used freely only for noncommercial personal or educational
purposes.

I look forward to any comments regarding or findings resulting from this
data. Enjoy.

Glenn

---------------
DataPoint v0.6
(c) 2001 G.A.Carlson/Xannah AS&E
scale= 2.260869565
Time (s) X (pixel) Y (pixel) x(ft) y(ft)
0 192 85 434.0869565 192.173913
0 100 85 226.0869565 192.173913
0 194 198 438.6086957 447.6521739 0
0.0336 194 197 438.6086957 445.3913043 -2.260869565
0.0671 193 197 436.3478261 445.3913043 -2.260869565
0.1007 194 199 438.6086957 449.9130435 2.260869565
0.1343 194 198 438.6086957 447.6521739 0
0.1679 194 199 438.6086957 449.9130435 2.260869565
0.2014 194 198 438.6086957 447.6521739 0
0.235 195 199 440.8695652 449.9130435 2.260869565
0.2686 193 198 436.3478261 447.6521739 0
0.3021 195 199 440.8695652 449.9130435 2.260869565
0.3357 194 197 438.6086957 445.3913043 -2.260869565
0.3693 194 197 438.6086957 445.3913043 -2.260869565
0.4029 193 198 436.3478261 447.6521739 0
0.4364 194 198 438.6086957 447.6521739 0
0.47 194 198 438.6086957 447.6521739 0
0.5036 193 197 436.3478261 445.3913043 -2.260869565
0.5371 193 199 436.3478261 449.9130435 2.260869565
0.5707 194 198 438.6086957 447.6521739 0
0.6043 194 197 438.6086957 445.3913043 -2.260869565
0.6378 195 197 440.8695652 445.3913043 -2.260869565
0.6714 194 198 438.6086957 447.6521739 0
0.705 194 197 438.6086957 445.3913043 -2.260869565
0.7386 194 198 438.6086957 447.6521739 0
0.7721 193 198 436.3478261 447.6521739 0
0.8057 196 197 443.1304348 445.3913043 -2.260869565
0.8393 194 198 438.6086957 447.6521739 0
0.8728 194 195 438.6086957 440.8695652 -6.782608696
0.9064 194 197 438.6086957 445.3913043 -2.260869565
0.94 193 197 436.3478261 445.3913043 -2.260869565
0.9736 194 196 438.6086957 443.1304348 -4.52173913
1.0071 193 196 436.3478261 443.1304348 -4.52173913
1.0407 194 195 438.6086957 440.8695652 -6.782608696
1.0743 194 196 438.6086957 443.1304348 -4.52173913
1.1078 193 196 436.3478261 443.1304348 -4.52173913
1.1414 194 196 438.6086957 443.1304348 -4.52173913
1.175 194 195 438.6086957 440.8695652 -6.782608696
1.2086 194 196 438.6086957 443.1304348 -4.52173913
1.2421 193 196 436.3478261 443.1304348 -4.52173913
1.2757 194 194 438.6086957 438.6086957 -9.043478261
1.3093 193 195 436.3478261 440.8695652 -6.782608696
1.3428 193 194 436.3478261 438.6086957 -9.043478261
1.3764 194 194 438.6086957 438.6086957 -9.043478261
1.41 193 193 436.3478261 436.3478261 -11.30434783
1.4436 193 193 436.3478261 436.3478261 -11.30434783
1.4771 192 195 434.0869565 440.8695652 -6.782608696
1.5107 193 194 436.3478261 438.6086957 -9.043478261
1.5443 193 194 436.3478261 438.6086957 -9.043478261
1.5778 192 194 434.0869565 438.6086957 -9.043478261
1.6114 193 194 436.3478261 438.6086957 -9.043478261
1.645 193 193 436.3478261 436.3478261 -11.30434783
1.6786 193 193 436.3478261 436.3478261 -11.30434783
1.7121 193 193 436.3478261 436.3478261 -11.30434783
1.7457 194 193 438.6086957 436.3478261 -11.30434783
1.7793 193 193 436.3478261 436.3478261 -11.30434783
1.8128 192 192 434.0869565 434.0869565 -13.56521739
1.8464 193 192 436.3478261 434.0869565 -13.56521739
1.88 193 191 436.3478261 431.826087 -15.82608696
1.9135 193 191 436.3478261 431.826087 -15.82608696
1.9135 154 237 348.173913 535.826087 -15.82608696
1.9471 155 237 350.4347826 535.826087 -15.82608696
1.9807 155 237 350.4347826 535.826087 -15.82608696
2.0143 155 236 350.4347826 533.5652174 -18.08695652
2.0478 155 235 350.4347826 531.3043478 -20.34782609
2.0814 155 235 350.4347826 531.3043478 -20.34782609
2.115 155 235 350.4347826 531.3043478 -20.34782609
2.1485 155 234 350.4347826 529.0434783 -22.60869565
2.1821 155 234 350.4347826 529.0434783 -22.60869565
2.2157 155 233 350.4347826 526.7826087 -24.86956522
2.2493 155 232 350.4347826 524.5217391 -27.13043478
2.2828 155 232 350.4347826 524.5217391 -27.13043478
2.3164 155 231 350.4347826 522.2608696 -29.39130435
2.35 155 230 350.4347826 520.0000000 -31.65217391
2.3835 155 229 350.4347826 517.7391304 -33.91304348
2.4171 155 229 350.4347826 517.7391304 -33.91304348
2.4507 155 228 350.4347826 515.4782609 -36.17391304
2.4843 155 227 350.4347826 513.2173913 -38.43478261
2.5178 155 226 350.4347826 510.9565217 -40.69565217
2.5514 155 226 350.4347826 510.9565217 -40.69565217
2.585 155 225 350.4347826 508.6956522 -42.95652174
2.6185 155 224 350.4347826 506.4347826 -45.2173913
2.6521 155 223 350.4347826 504.173913 -47.47826087
2.6857 155 222 350.4347826 501.9130435 -49.73913043
2.7193 155 222 350.4347826 501.9130435 -49.73913043
2.7528 155 221 350.4347826 499.6521739 -52
2.7864 155 220 350.4347826 497.3913043 -54.26086957
2.82 156 220 352.6956522 497.3913043 -54.26086957
2.8535 156 219 352.6956522 495.1304348 -56.52173913
2.8871 155 218 350.4347826 492.8695652 -58.7826087
2.9207 156 217 352.6956522 490.6086957 -61.04347826
2.9542 156 217 352.6956522 490.6086957 -61.04347826
2.9878 156 216 352.6956522 488.3478261 -63.30434783
3.0214 155 215 350.4347826 486.0869565 -65.56521739
3.055 155 214 350.4347826 483.826087 -67.82608696
3.0885 156 212 352.6956522 479.3043478 -72.34782609
3.1221 155 212 350.4347826 479.3043478 -72.34782609
3.1557 155 210 350.4347826 474.7826087 -76.86956522
3.1892 155 210 350.4347826 474.7826087 -76.86956522
3.2228 155 209 350.4347826 472.5217391 -79.13043478
3.2564 155 208 350.4347826 470.2608696 -81.39130435
3.29 155 207 350.4347826 468.0000000 -83.65217391
3.3235 155 207 350.4347826 468.0000000 -83.65217391
3.3571 155 205 350.4347826 463.4782609 -88.17391304
3.3907 155 204 350.4347826 461.2173913 -90.43478261
3.4242 155 203 350.4347826 458.9565217 -92.69565217
3.4578 155 202 350.4347826 456.6956522 -94.95652174
3.4914 155 201 350.4347826 454.4347826 -97.2173913
3.525 155 200 350.4347826 452.173913 -99.47826087
3.5585 155 199 350.4347826 449.9130435 -101.7391304
3.5921 156 198 352.6956522 447.6521739 -104
3.6257 155 197 350.4347826 445.3913043 -106.2608696
3.6592 155 196 350.4347826 443.1304348 -108.5217391
3.6592 155 224 350.4347826 506.4347826 -108.5217391
3.6928 155 224 350.4347826 506.4347826 -108.5217391
3.7264 155 222 350.4347826 501.9130435 -113.0434783
3.76 155 221 350.4347826 499.6521739 -115.3043478
3.7935 155 220 350.4347826 497.3913043 -117.5652174
3.8271 155 219 350.4347826 495.1304348 -119.826087
3.8607 155 217 350.4347826 490.6086957 -124.3478261
3.8942 154 217 348.173913 490.6086957 -124.3478261
3.9278 154 215 348.173913 486.0869565 -128.8695652
3.9614 154 214 348.173913 483.826087 -131.1304348
3.9949 154 213 348.173913 481.5652174 -133.3913043
4.0285 154 212 348.173913 479.3043478 -135.6521739
4.0621 154 211 348.173913 477.0434783 -137.9130435
4.0957 154 210 348.173913 474.7826087 -140.173913
4.1292 154 209 348.173913 472.5217391 -142.4347826
4.1628 153 208 345.9130435 470.2608696 -144.6956522
4.1964 153 206 345.9130435 465.7391304 -149.2173913
4.2299 153 205 345.9130435 463.4782609 -151.4782609
4.2635 153 204 345.9130435 461.2173913 -153.7391304
4.2635 152 238 343.6521739 538.0869565 -153.7391304
4.2971 151 238 341.3913043 538.0869565 -153.7391304
4.3307 151 236 341.3913043 533.5652174 -158.2608696
4.3642 151 235 341.3913043 531.3043478 -160.5217391
4.3978 151 233 341.3913043 526.7826087 -165.0434783
4.4314 151 232 341.3913043 524.5217391 -167.3043478
4.4649 151 231 341.3913043 522.2608696 -169.5652174
4.4985 150 231 339.1304348 522.2608696 -169.5652174
4.5321 150 230 339.1304348 520.0000000 -171.826087
4.5657 150 229 339.1304348 517.7391304 -174.0869565
4.5992 149 227 336.8695652 513.2173913 -178.6086957
4.6328 149 226 336.8695652 510.9565217 -180.8695652
4.6664 149 225 336.8695652 508.6956522 -183.1304348
4.6999 149 224 336.8695652 506.4347826 -185.3913043
4.7335 149 223 336.8695652 504.173913 -187.6521739
4.7671 149 221 336.8695652 499.6521739 -192.173913
4.8007 148 220 334.6086957 497.3913043 -194.4347826
4.8342 148 219 334.6086957 495.1304348 -196.6956522
4.8678 148 218 334.6086957 492.8695652 -198.9565217
4.9014 147 217 332.3478261 490.6086957 -201.2173913
4.9349 147 215 332.3478261 486.0869565 -205.7391304
4.9685 147 214 332.3478261 483.826087 -208

===========
Glenn A. Carlson, P.E.
St. Charles Community College
St. Peters, MO USA
gcarlson@chuck.stchas.edu