although some outdated bombs were used as practice the issue of ww1 and interwar US bombs is more complex: Here the development of these bombs, that I compiled some time ago - not a very easy business as some identical appellations was re-used to designate different models....while the same models also changed their designation at each re-organization.
Type Gros Andreau 1917-1918
25lb Demolition Mk I
50lb demolition Mk I
100lb Demolition Mk I
Fragmentation 1917-1918
17 lbs (rejected 3 in artillery shells)
25 lbs (British Cooper bombs)
1918
High Capacity Drop (Demolition)
Olive drab stenciled in black with 1 in black band at the center of gravity
Mk I 104 lbs 47 in x 7.5 in
Mk II 22lbs 28.25 in x 4.75 in
MkIII 51.5 lbs 36 in x 6 in
Mk IV 260lbs 47.25 in x 12.20 in
Mk IV-A (duplicate of theFrench 100 kg)
Mk V 550lbs 59.04 in x 16.53 in
Mk VI-A 1,000lbs 62.75 in x 20.875 in
Fragmentation
Olive drab stenciled in black with 1 in blue band at the center of gravity
Mk I 94lbs 58.3 in x 6 in
MkII 19lbs 30.1 in x 2.925 in
MkII-A 19lbs 30.2 in x 3 in
MkII-B (copy of the English Cooper bomb)
MkIII 49lbs 50.38 in x 4.7 in
Incendiary
Olive drab stenciled in black with 2x 1in red bands 3 inches from tip, 2 inches apart
Mk I 40lbs 36 inx 6 in (balck powder and turpentine)
Mk II 46lbs 36 in x 6 in (intensive - thermite)
Mk III 100lbs under development
1918-30
Mk I Drop 100lb
Mk II Drop 25 lb
Mk III Drop 50 lb
MkIV Drop 300lb
MkV Drop 600lb
MkVI Drop 1100lb
1930s
MkI series Demolition:
welded joints circumferential and longitudinal. tail fuze only (no arming vanes)
25lb (previously drop Mk II)
50lb (previously drop Mk IIII)
100lb
MkI MI series Demolition:
nose fuze with arming vanes (and for 300 and 600lb, tail fuze too with arming vanes)
Fins strengthening braces
100lb
300lb
600lb
MkIII series demolition:
both noze and tail fuzes with arming vanes
No longitudinal welds, only circumferential ones
Fins build at a single unit, with stengthening fin braces.
100lb (previously drop Mk I-C)
300lb (previously drop Mk IV-C)
600lb (previously drop Mk V-C)
1100lb (previously drop Mk VI-C)
Cylindrical body series:
Nose and tail fuzes with arming vanes
fina ssembly designed as a unit, with strenghtening braces.
2000lb Mk I,
2000lb MkI MI,
2000lb MkI MII
Standard production 1930
MkIII series demolition:
100lb MkIII
300lb MkIII
600lb MkIII
1100lb MkIII
2000lb MkI MII
Substitute standard for production
100lb MkI MI
300lb MkI MI
2000lb MkI MI
Obsolete (Training)
25lb Mk I
50lb Mk I
Limited standard (War reserve)
100 lb Mk I (previously drop Mk I)
600lb Mk I MI
2000lb Mk I
1930 Fragmentation
Standard production 1930
30lb M5 (ring type body)
Limited standard (War reserve)
17lb Mk II (previously fragmentation drop Mk II-A)
25lb Mk III (previously fragmentation drop Mk II-B)
1930 Dummy bombs (empty)
40 lb Incendiary Mk I
40 lb Incendiary Mk II
25 lb Demolition Mk I
50 lb Demolition Mk I
100 lb Demolition Mk I
300 lb Demolition Mk I
1930 Chemical
Nose fuzes only 9with vane for 30lb)
30 lb MI chemical
50ln Mk I demonstration
The bomb shown on the photos has an "Eiffel pattern" (Gros Andreau), without reinforcing fin struts, and with circumferential as well as longitudinal wielding lines and a MarkIII lettering on the mid band - if it is an original and not a fake, we have here one of the earliest patterns "drop MkIII" 51lbs bomb.