Main Type 21
- Last UpdatedDec 01, 2025
- 1 minute read
This cutout is similar to main type 21 except that the top is elliptical, cf. the figure below.
Figure 2:28. Main type 21, radii.
This cutout is similar to main type 21 except that the top is elliptical, cf. the figure below.
Figure 2:28. Main type 21, radii.