International: 281/283/304/303/303m platforms 1-5
New Street:
Platform lengths – Birmingham New Street
Notes
The platform lengths shown are dimensioned top of ramp to top of ramp and an allowance for signals, stop boards, buffer stops & stopping tolerance must be deducted from these figures to arrive at effective lengths.
Platform Lengths:
1 - 350 metres (383 yards)
2 - 322 metres (352 yards)
3 - 322 metres (352 yards)
4 - 359 metres (393 yards)
4C - 98 metres (107 yards)
5 - 265 metres (289 yards)
6 - 315 metres (344 yards)
7 - 318 metres (348 yards)
8 - 339 metres (371 yards)
9 - 321 metres (351 yards)
10 - 321 metres (351 yards)
11 - 333 metres (364 yards)
12 - 236 metres (258 yards)
Both from
https://sacuksprodnrdigital0001.blob.core.windows.net/sectional-appendix/Sectional Appendix full PDFs March 24/London North Western (South) Sectional Appendix March 2024.pdf
Euston platform 1 is 398m from the same source.
Full 16 coach sleeper consist plus locomotive is ~380m today.