BOMB DAMAGE ASSESSMENT OF BRIDGES IN NORTH VIETNAM THROUGH 1966

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78S02149R000100070004-9
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 7
• Document Creation Date: December 19, 2016
• Document Release Date: September 20, 2004
• Sequence Number: 4
• Publication Date: May 1, 1967
• Content Type: MEMO

05/06/01 : CIA-RDP78S02149R0
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Chief, Tin
Chief, D/T
Verm
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1 1967 mo,
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NGA Review Complete
sessment of Bridges- in North Vietnen Through 1966
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1. In r/October 19651 'spent
two weeks at Arlington Nall (DIA) searching all available photography for
eonfirmmtion of the nuOber of dmmaged/destrcomd bridges in North Vietnam.
This search was undertaken in conjunctions with DMA personnel, and it WM
comaenly agreed that 121 bridges were damaged/destroyed at that time. This
total represented about one-seventh of the 733 bridges DIA was reporting in
their I1y Bulletin (see the attached DTA Balletin).
2.ny the sad of 1966 the total onWber of bridges confirmed by aertel
photopenhy to have been demaged/destrOyed had risen to 393. This figure in
eludes highway; railroad, and combination Ritilwy bridges. Of this total 362
bridges babe= seriously damoged one or more times for a total of 552
serious damage occurrences (seethe attached table
3. The: difference between CIA sad DTA estimates of total bridges damesedi
destmed lies largely in the methodology used. CIA relies exclusively on
aerial photography; because photography in the 'only source whidh provides suffi-
cient information to estimate bridge damage end the cost of bridge damage tp
the Merth Vietnamese. DIA apparently relies heavily on pilot reports, whleh
have proven to be overly optimistic in estimating the damage actually inflizted
dories araid. There is substantial agreement between CIA and =A on the number
or railroo4 bridges and combination bridges because the total nulber of struc-
tures of these tynes is relatively low. There is a wide difference; however,
between the two estimates on the number of highway bridges.
4, The differences can be recasoils4 only if the methods of Rnlysis and
sources of information on, boab damage are the same. To derive a meaningfu
cost estimate of destrUction to bridges in North Vietnam; T/CST aunt rely o
poet Arne PhotogrePhy of each bridge attacked. The Dietary Analysis Staff of
NPIC prepares Photo Interpretation Bulletins (P1Wit) and they are distriboted to
the intelligence Commit:, in general. This staff does not attempt to correlate
information on daily air strikes against the photography they receive. Isiteid;
thar Sean every available mission and report to T/CSIT and to the Community: only
infortmition on those bridges with new or additional &meg,. Agreement bet wen
CIA and BMA on the total =giber of bridges dameged/destroyed would mean that the
analysts responsible for counting bridges in DIA would have to use the same
system as CIA. The differenee in the methodology, definition of damage? and
p IA review(s) completed.
Is)GA Review completed.
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of PTC1U4 e eon figure. The reported by
oarr by aerial photogra To OVOld
ehed figures onbrldges statizag
ion were ueo4 to arrive at the estimate and lobeth3
reeM rebuilt bridges aa more than one
Distribution:
Orig. & 1 - Ades
1 -
1
1 -T
RR/IT/CST:
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CST (file)
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(1 May 67)
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'iaoic 2
Bridge - Bomb Damage Assessment
in North Vietnam
First Quarter 1967
Type of Bridge
Highway
Railroad (only)
Hanoi - South
Hanoi - Dong Dang
Hanoi - Haiphong
Hanoi - Lao Cal
Kep-Thai Nguyen
Total RR
Combination
Hanoi - South
Hanoi - Dong Bang
Hanoi - Haiphong
Hanoi - Lao Cal
^ Ker,-Thai Nguyen
Strikes Resulting in Serious Damage
Initial Hits
Re-Hits Bridge Totals
Total _ Total
Original By-Pass Total Original By-Pass Total Total ,Seriously `Serious Damage
_
Bridge's Bridge's Bridge's Bridge's Bridge's Damaged Damaged Occurrences
5
0
0
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Total Thru March 1967 7
o 5 17 2 19 6 5 24
J
o o o
o o o o o o
L.
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0
4
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O o o
O 0 o
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Bridge - Dnn7D D=age Asoccuum Aorth Vietnam
1966
Type of Bridge
Highway
Railroad (only)
Hanoi - South
Hanoi - Dong Dang
Hanoi - Haiphoiag
Hanoi - Lao Cal
Kep-Thai Nguyen
Total RR
Combination
- Hanoi - South
Hanoi = Dong Dang
Hanoi - Haiphong
Hanoi - Lao Cal
Kep-Thai Nguyen
4 Total Combination
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Total 1966
Strikes Resulting in Serious Damage
Initial Hits
Original
Bridge's
BY-Pass
Bridge's
Total
Bridge's
Original
Bridge's
120
9
129
90
25
8
33
26
0
o
1
o
o
7
7
11
1
1
o
33
41
38
Re-Hits Bridge Totals
Total_ Total
By-Pass Total Total ISeriously 'Serious Damage
Bridge's Bridge's Damaged Damaged Occurrences
0
90
141
129
- 219
8
34
28
33
67
o
o
o
o
3
o
11
,:-
_,
7
18
o
o
__1
1
1
8
46
37
41
87
11
11 1 12
11
11
23
2
0 0
2
2
2
0 1
1 0 1
1
1
2
1
o-0
1
1
1
11
4 15
12 1 13
15
15
28
21 185
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Table 4
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Bridge - Bomb Damage Assessnent ir North Viet=
1965
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Type of Bridge
Highway
Railroad (only)
Hanoi - South
Hanoi - Dong Dang
Hanoi - Haiphong
Hanoi - Lao Cal
Kep-Thai Nguyen
Total BR
Combination
Hanoi - South
Hanoi - Dong Deng
Hanoi - Haiphong
Hanoi - Lao Cal
Keo-Thai Nguyen
Total Combination
4
Total 1965
Strikes Resulting in Serious Damage
Initial Hits
Re-Hits
Original By-Pass Total Original By-Pass Total
Bridge's Bridge's Bridge's Bridge's_ Bridges Bridge's
135: 2
8
173
4
137
30 '
17
1
2
0
13
5
0
32
8
177
3 '
39
6 30
2
0
0
0
2
0
0
Bridge Totals
Total Total
Total Seriously Serious Damage
Damaged Damaged Occurrences
153
3
21
2
0
14
0
0
3
0
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137 167
17
2
3
13
0
37 32
20
2
0
18
260
177
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