THE IRON GATES OF THE DANUBE

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP79T01049A000500080001-4
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 15
• Document Creation Date: November 9, 2016
• Document Release Date: June 8, 1999
• Sequence Number: 1
• Publication Date: June 16, 1952
• Content Type: SUMMARY

Approved For R Base 19 I~ tDP79T0M49A000500080001-4
SECURITY R. ,.: . .
THE IRON GATES OF THE DANUEE,
CIA/RR iP-263
16 June 1952
Note
The data and conclusions contained in this report
do not necessarily represent the final position of
ORR and should be regarded as provisional only and
subject to revision. Additional data or comments
which may be available to the user are solicited.
This report contains information available to ORR
as of 16 Juno 1952
WARNING
This material contains information affecting the
national defense of the United States within the
meaning of the espionage laws,, Title 18, USC,, Secs.
793 and 794# the transmission or revelation of which
in any manner to an unauthorized person is prohibited
by law.
G1 NTR.!L INTELLIGEIEE AGENCY
Office of Research and Reports
Approved For Release 1999/09~ IA-R DP79TO1049A000500080001-4
 Approved For F ease 1999/I IA-RDP79T 49A000500080001-4
SECURITY INFORMATION
Table of Contents
Sun!Tlaryo a. a o a..?? 0 0 a..
A. General Description of tha Geology and River Regime. ? ? . 2
B. The Gorges of the Iron Gates .
Ta The First Gorge. o .
II. The Upper Djerdap (Perdap) Gorge . o o o e . . . ? * 4
III. The Kazan Gorge (Lower Berdap) . . ? a ? a a ? o .
25X1 C iv. The Sipe Gorge ( r3c1ud .g the Iron Gate)
Appendix Ag Sources and Evaluation of Sources. a . m a a , 10
1, Evaluation of Sources o . ? ? ?
a a . . . 0 0 0 10
2. Sources o . . S. a ? . o ? a e a o o s ? ? ? o ? . 10
a. Documents o o ? . a ? o . , a o s ? . . . ? . 10
be Maps. ? a a e a ? . . ? ? . o ? . 0 0 . 0 o . 11
List of Illustrations
Following Page
Fig. la The Kazan Gorge ?
Fig, 2 a Green. ? a a a , ? a . ? a e 0 . 0 . ? a ? * . . 0 0 2
Fig. 30 The Kazan Gorge looking downstream, a a a a?. a a a 3
Fig, 1. The Kazan Gorge looking upstreamo o . a . . . a . a . 4
Fig. 5, Little Kazan Gorge looking downstream o a a . . . a a 4
Fig. 6. Looking downstream from Krn. 947 (Sip Gorge) . , . ? a 5
Approved For Release 1999/09/27 : CIA-RDP79TO1049A000500080001-4
SECRET
 Approved For Release 1999/09/27 : 79TO1O49AOOO5OOO8OOO1-4
fft
SECURITY INFORMATION
F'o11ow,,.3 ng Page
Fig0 7o The Prigrdaa
a o 0 0 a o a 0 0 0 o 0 0 w ? a 0 0 4 6
Figo 80 Downstream entrance of Sip Caxaal. o o s o o a o a 0 c o
Map
Geology of the Iron Gates Sector of the Danube (CIA 12273,'
Approved For Release I 999/09/27SEC, DP79TO1 O49AOOO5OOO8OOO1-4
 Approved For Release 1999/0# HLEQI A-RDP79TO1049A000500080001-4
Ct~ ~ ilftw
SECURITY INFORMATION
THE IRON GATES OF THE DANUBE
Summary
From Golubac9 Yugoslavia, eastward to Turnu Severine Rumania, the
Danube River cuts across the Southern Carpathians, flowing for 93 miles
through a series of gorges and basins. These gorges and basins, col-
lectively, are commonly known.as the Iron Gates. Used in the singular,
the term "Iron Gate" applies only to a specific point in the Danube at
Sip Gorge, immediately northwest of Turnu Severin (see map CIA 12273),
The Danube varies greatly from place to place in depths width,
and velocity. In the gorges of the Iron Gates the valleys are V-shaped.
In many places the sides slope precipitously down to the water's edge
and the river fills the entire valley from side to side (see Figure l),*
A road traverses the entire length of the Iron Gates.only along the
Rumanian hank. The channel is deep and narrow, with occasional pot holes
scoured out to depths below sea level,'and the current is rapid. In the
basins between the gorges the river becomes shallow and spreads out to
twice its width in the gorges., and its flow is more sluggish. The channel
is divided by sand banks and islands, and occasional small discontinuous
plains border the river. The flow of the Danube also varies seasonally,
and both high and low water present navigational problems., At the en-
trance and exit of each basin, took bars or reefs give rise to rapids
and whirlpools at low water and may be completely submerged at high
watery These reefs and bars are the major hazards to navigation along
* gures accompany only the first four copies of this report,
Approved For Release I 999ISG ILIA-RDP79TO1049A000500080001-4
I
 Approved For F kjFease 1999/09ffCpff -RDP791$ 049A000500080001-4
$ECURI'L&INFORM
25X1 C
the Danube
No micro geologic survey; have been made of the Iron Cates section
of the Danube
however, is an ?nferece and should be regarded as such.
A. General Description of the Geology and River Regime
Throughout the 93~-e stretch of the. Iron Gates, the Danube cuts
across the Southern Carpathians in a series of gorges and basins. The
broad structural features of the Southern Carpathians are similar to
those of the Alpine-fold mountains of other parts of Yugoslavia, where
great and complex ove:"folding and intense faulting have occurred. A
cross section of the cleft out by the Danube across the Carpathian
system clearly shows this folded structures and the gorges provide the
finest example in Europe of a defile incised by fluvial " erosion. The
Iron Gates also illustrate on a large scale a characteristic and widen
spread feature of the Balkan Peninsula the linking together of the
drainage of former lake basins through interconnecting gorges out at
the close of the Tertiary age.
Between Ram, 33 kilometers up stream from Golubac (Km. 1,015), in
the west and Kladbvo (Kma. 935) in the east, the Danube decends from
230 to 130 feet above sea level.* Consequently, even the average
ome~rage is measured from Sulina, Rumanian at the mouth of the
Danube.
Approved For Release 1999/09/itt t-RDP79TO1049A000500080001-4
25X1C
 Approved For Release 1999/09/27: CIA- DP79T01049A000500080001-4
-3- NECflET
SECURITY INFORMATION
gradient in the Iron Gates is far greater than that in the Hungarian
Basin to the west or in the Rumanian Basin to the east. The volume of
the Danube varies greatly from season to season, and navigational diffi-
culties are concomitant with both high and low water. Local variations
between mean high and mean low water is between 29 and 36 feet. The
average flow of the river at the lower end of the Iron Gates is 205,000
cubic feet of water per second, For comparison, the Potomac at Point
of Rocks,. Maryland, has an average flow of only 11,560 cosecs and an
absolute maximum, recorded only once, of 480,000 cusecso
The gorges (see Areas HIV on the map) are the primary concern of
this study, From west to east they are:
I. The First Gorge
II. The Upper D3erdap (Derdap) Gorge
III. The Kazan (Lower Djerdap) Gorge
IV. The Sip Gorge (including the Iron Gate)
B, The Gores of the Iron Gates
I. The First Gorge
About four miles below Golubac, where the Danube passes through
the first defile, the river bed narrows to a width of 1,050-1,200 feet,
The gorge is about 5 miles long, and on the Yugoslav shore the walls rise
almost sheer from the surface of the river to a low plateau about 1400 feet
high. On the Rumanian side the walls slope more gently and do not exceed
1,100 feet in height. The gorge is carved through a variety of crystalline
rocks, At its upper end is the cherty limestone rock of Babakaj, which
stands out several feet above the surface of the water, and at its lower
end is the Stenka barrier, a submerged granite reef, To make the Stenka
cataracts navigable, over a mile of the channel was dynamited to a width
Approved For Release 1999/09/27 : CIA-RDP79TO1049A000500080001-4
.!
 SECRET
Approved For Rase I 999211'OCIW -#"Y@i 49A000500080001-4
of about 800 feet,
The first gorge ends at the Stenka cataracts, and for the next 10
miles the Danube flows through the Liubcova Basin, which varies in width
from 2,700 feet to almost a mileo The basin is made up of various types
of crystalline., which are covered with Tertiary rocks to a large extent,
II. The ter D erda ( 3erdap) Corge
Just below the bend of the Danube at Bgrzaca (Km. 1017) the
second cataract, located at the slate bank of Kozla and the reefs of
Dojke, marks the beginning of the second gorge. Here the river narrows
to less than 1,000 feet. For a distance of 8 miles the Danube has cut
a gorge only 600 to 900 feet wide through the highest peaks of the South
Carpathians, whose walls rise sharply from water level to altitudes of
over 1,600 feet on either sides Here the river has cut through various
types of rocks that include limestones and shales, as well as ancient
crystalline schists.
The bed of the Danube is interrupted by several rock bars that
are exposed only at low water* From northwest to southeast they are:
(1) Kozla and Dojke, composed of light, splintery Neocomian limestone,
(2) Tzias and the Tahtaljas, composed of quartz porphyry conglomerates;
and (3) Vrani, below Greben (Km. 999) which is Tithonian limestone.
Greben, itself, is a great out-thrusting rock 625 feet high (see Figure 2),
Channels with widths of 200 feet and lengths varying from 1 to 2 miles have
been blasted through these barriers.
Below Greben the valley opens into the Miocene Basin of Don.i
Milanovac (Km. 993), The basin is about 8 miles long and over 1 mile in
breadth at its widest pointo At the lower end of the basin is the rock
Approved For Release 1999/09/RQAufff RDP79TO1049A000500080001-4
 Approved For Release 1999/09/27SECIfIDP79T01049A000500080001-4
? SECURITY INFORMATION *Wf
bar of Juc (Km, 989), which is composed of serpentine" Navigation
follows a I$LOO foot channel blasted through the -barrier,
111 -2 Kazan (Lower Djerdap) Garge
Below Juc the valley narrows progressively to its third and
most spectacular gorge, which is located at the point where the river
course changes from southeast to northeast. Near Kazan (see Figures
3 and Ia)p the river is restricted to a width of 600 feet, the width of
the Potomac at the Georgetown Reservoir. For a considerably longer
stretch the width is less than 1,9500 feet, approximately that of the
Potomac at Memorial. Bridged The narrowest parts of the third gorge are
(1) the Great Kazan defile9 located between Kazan and Dubova (km. 970),
beyond which the valley widens into a small Helvetian basin 1,,8OO feet
in breadth, and (2) the Little Kazan defile (see figure 5) between Dubova
and Ogradina. Both defiles have been cut through Tithonian limestone.
In this stretch the Danube'is about 60 feet deeps the current is char-
acterized by eddies that have scoured out a number of large pot holes in
the river bed" Many of the pot holes are as much as 160 feet deep, with
their bottoms points below sea.levelo The Kazan gorge has the form of a
canon sunk within an ancient valley, whose floor today forms a clearly
defined platform or terrace that slopes gently back from the pretipitous
walls of the defile. On the Rumanian sides several small tributaries
enter the Danube through normal valleys, There are no'right bank
tributaries since the gorge is cut into the northern end of abroad out-
crop of limestone, which forms a miniature karat plateau that is com-
pletely devoid of surface drainage"
SECRE
Approved For Release 1999/09/27: CIA-R DP79TO1049A000500080001-4
 Approved For Release 1999/09/27 : CIA-RDP79TO1049A000500080001-4
SECRET`
SECURITY INFDRMATIO t
The third gorge ends at the Islet of Ograndia (Kris 962),which
is composed of sand and gravel washed down from the Kazan. Between
Ogranina and another islet of similar formations Ada Kaleh (or Adakales
Turkish for Castle Island), is .,he Or>ova? Basing ;where the Tertiary rocks
am less resistant than those of other parts of tha Iron Gateso As in the
other basins., the Danube hugs the southern banks on the Yugoslav side and
the valley walls rise steeply. On the Rumanian side the river is bordered
by valley flats and plains of small tributary deltas and the valley walls
slope upwards. At many points in the Orsova Basin the river is more than
a half mile in width. At the town of Or9ova (Kmo 956), the' Cerna River,
the only large northern tributary of the Danube in this section, has cut
a deep valley that forms an important natural route into the heart of the
Carpathians
o
IV. The Sip Gorge and the Iron Gate
The last gorge of the Iron Gates begins just below Ada Kaleh
(Km.950)9 although it includes the Iron Gate itself8 this gorge is less
spectacular and. wider than the Kazan defilesa Even at Sips the river is
more than 1,9500 feet wide, and the valley walls are low and gently sloping
(see Figure 6). The Sip Gorge is out in steeply inclined and almost
vertical schistB, limestones and sandstones. Traces of Tertiary lake
terraces are found at considerable altitudes above the gorge itself0 Just
above Sip there is a very large rock bar in the river bed--the Pri.grada--
which interferes seriously with navigation on the Danube. Strictly
speaking, this rock bar is the Iron pate (see Figure 7). The Prigrada is a
great reef' over 5,600 feet long and 10600 feet wide, that extends almost
completely across the river. At low water the re of rock stands above the
surface of the Danube and forms rapids, but at high water it is completely
Approved. For Release 1999/09/2SE tRDP79T01049A000500080001-4
 Approved For Release 1999/09/27 : CIA- M MT 01049A000500080001-4
`~ SECURITY INEORMAT _
submerged. Deep pot holes have been abraded in the Prigrada, one of
which has a depth of 170 feet the last 53 being below sea level,
Navigation across the Prigrada has been made possible by blasting
the Sip or Iron Gate Canal along the Yugoslav bank. The.canal is 262
feet wide and 1 1/3 miles long (see Figure 8).
Even though the other gorges are narrower, more canyon-like, and
more awe-inspiring than Sip Gorge., with the Iron Gates this stretch.is
the greatest navigational bottleneck along the Danube. In the Sip
Gorge, the riverp has a fall of about 16 feet, and in October,, the low.,
water season, the current runs up to 12 knots., upstream navigation
through the Sip Canal is possible only with the aid of auxiliary haul-
age, using steam-locomotive traction. Tows proceeding upstream consist
of the steam locomotive and a powerful tug that pull three barges at the
most. Along the left side of the Prigrada an old, unimproved navigation
channel that at certain water levels is practicable for tom for periods
aggregating 216 days a year. These periods, however, occur at various
times throughout the years and the passage,, at best,, is dreaded by
Danubian pilots.
A short distance downstream from the Iron Gate is the Little Iron
Gate (Km. 9L3), a group of rocks -in the middle of the river that form a
minor hazard to navigation. They are composed of biJotitembearing quartzite
and foliated, fine grained granite. The eastern flank of the Carpathian
system lies several miles downstream from the Little Iron Gate, and beyond
it the landscape begins to change. Sandy islands appear in the river.,
which is slightly incised into the soft deposits that cover the region
generally., The relief is subdued, the hills recede,, and the river flows
within series of river terraces carved in the less resistant types of
Approved For Release 199
RAT: CIA-RDP79TO1049A000500080001-4
 Approved For Release 1999/09/27. CIA- 7
04%4Q00500080001-4
25X1 C
I
Tha,sa terra,-es a 10 to a' .t s.
4"a7`k '. i F s ~; .. A.+ b:.T~:3 whi--h mark the.
lrc,n Ca am;
m . limit ce t b
Approved For Release 1999/09( r-RDP79TO1049A000500080001-4
 5X1 C
Approved For Release 1999/09/27 : CIA-RDP79TO1049A000500080001-4
Approved For Release 1999/09/27 : CIA-RDP79TO1049A000500080001-4
 Approved For Rase 1999/09/ (~: 4bP79TOf049A000500080001-4
SECURITY INFORMATION
APPENDIX A
SOURCES AND EVALUATION OF SOURCES
Evaluation of Sources
All the sources listed below are accurate and reliable.
In the list of documents, Items l9 2, 8 and 10 may be considered pri-
mary sources since they are, for the most part, based on field work by
their authors in the area of the Iron Gates. Although more than 40
years old they are still the best authorities. The other sources are
secondary or tertiary.
All four maps listed are recommended as authoritative,
highly informative and reliable. The first three stem fxum official
sources.
2. Sources
a. Documents
( 1) Cvijic, J., "Entwicklungsgeschichte des Eisernen Tores,"
Petennanna Mitteilungen, Ergsnzungsheft?N0. 160, 1908.
( 2) Schafarzik, Franz, "Kurse Skizze der geologischen
Verh'altnisse and Geschichte des Gebirges an Eisernen Tore and der
unteren Donaua" F?o'ldi i'Kozlon ,(Budapest) Vol. XXXIII, July-September
1903.9 pp. 402-4350
( 3) Sevastos, Romulus, "Sur le . DAfile des Fortes de Fer et sur
le Coura Inferieuur du Danube," Bulletin de la Societe GeologicDue de
France, 4th series, Vol. 4, No. 5a 1904, pp.-666-678.
( 4) Naval Intelligence Division, Jugoslavia,* Vol. I, 191414,
and Vol. 1119.19450
( 5) Toula, Franz, "Uber der Durchbruch der Donau durch das
Banater Gebirge," Vort'rage des Vereins zur Verbreitung naturw*
Approved For Release 1=17 : CIA-RDP79TO1049A000500080001-4
 Approved For Rase 1999/0 p79Tf 49A000500080001-4
SFCURI II
Kenntnisse in Wiens Vol. XXXV, No. 9s Wein 1895-
25X1 C
( 7) Vidal de la B3-aches P., et a1., Geogra pphie n verses ees,
Vol. VII, Part 2, 19340
( 8) Barliari, Po, Gros, L., 2-t Rap]ports de la Commission
Compose desIngenieurs ttranggrs, NendtirCh, Gusztav, Budapest, 18790
( 9) Edwards, Lovett F., Danube Streams London, 191100
(10) Gonda, Bela, von, Die RAC ierune des Eisernen Thores,
Budapest, 18960
b. M, a
(1) Karte der Donau von Ulm bis zur Mjindung, ls150,000 copied
by USFA, oDE, Salzburg,, 1948.
(2) Plovidbena Karta Dunava Pruga: Bed-Bratislava-Wdimpe'dta-
Beograd-Turn Severin Radujevac, erdapski Sektor, 1:10,000, Dr'avna
Recna Plovidba, Kra1jevine Jugoslavi)e, 1931.
(3) Plans et Dessins Annexes aux Rapports de la Commission
dos des In nieurs ttrangers.*?, Nendtirch, Gueztav, Budapest,
18790
(4) Az Alduna Geologiai Terkepe a Hajoz*si.Adakalyok Atnezseteval,
1:U!.000. from Foldtani 0Z1 ny, Vol."XXXIII, 19030
Approved For Release 1999/09/27 : CIA-RDP79TO1049A000500080001-4
EET