The
rescue project of Philae
When
the second Aswan dam was opened in 1971, Philae – dating from Ptolemaic times
and regarded as the most beautiful of Egyptian temples – was trapped beneath
the waters between the old and the new dam . UNESCO, aided by the Egyptian
government, sponsored the rescue of the temples in an enterprise of imagination
and skill on a grand scale .
A coffer dam was constructed around the island,
the water was pumped out, and the temple complex was dismantled and re-erected
on the neighboring island of Agilkia, safe above the Nile waters .
The concern of the world for the preservation of these
ancient treasures and the active measures taken through the good offices of
UNESCO for their rescue is something in which the nations involved can take
unselfish credit . Politics, creed, colour and race have been forgotten in the
current united endeavour to save Philae . The cost of this latest operation in
UNESCO's Nubian campaign was originally estimated at $13,700,000, of which the
Egyptian government pledged one-third . The Tutankhamun Exhibition, organized
by the British Museum, raised some £650,000 for the project in London alone .
The fate of Philae
The fate of Philae has concerned Egyptologists since
the old Aswan Dam was built by the British during the years 1899 to 1902 . The
dam was a large undertaking even by modern standards, for it is over a mile
long, 130 feet high and 100 feet thick at the base . When its 180 sluice-gates
were closed the trapped Nile waters flooded 140 miles back to the Sudanese
border . The height of the dam was at first restricted because of the protests made
by people interested in preserving Philae and other temples and monuments from
submersion .
Before the building of the dam, the island of Philae
had always stood clear of the river, safe on its granite foundation against the
turbulent rush of the flood with its abrasive silt . Once the dam went into
operation, the annual inundation trapped by it covered Philae for nine months of
each year, and the temples remained partially submerged until the sluice-gates
were opened in March to release the silt-laden water to the parched farmland of
Egypt . After the end of November, when practically all the valuable suspended
silt had passed through the sluices and the water was comparatively clear, the
gates were gradually closed and the lake above the dam was allowed to fill
until it reached its peak in February and the cycle of irrigation recommenced .
In 1895, before the Aswan Dam was built, the engineer
in charge, Captain Henry George Lyons, was asked to underpin the monuments of
Philae so that they could withstand the submersion . This he did ; he also
excavated part of the site where he discovered the remains of some Christian
churches . As it turned out the submersions were not altogether bad ; they
saved the temples from erosion by sand-storms and helped to remove salt
deposits which were injurious to the stonework . Regular inspections of the
site showed that it had suffered less damage than might have been expected .
The paintwork had of course been washed away but the stones had remained in
position, and as the water only receded during the hot summer months when
tourists were at a minimum, the temples were to some extent protected from the
attentions of souvenir . The present removal of the monuments gives another
opportunity for excavating the site as well as the unexplored ground beneath
the temples, a bonus for the salvage operation .
In 1955 fate once again struck Philae . To support the
rapidly increasing population of Egypt President Gamal Abdel Nasser decided to
construct the Saad-el-Aali ( The Aswan High Dam ) . On 14 May 1964 he and the
Soviet Prime Minister Nikita Khrushchev together pressed the button which blew
up the sand barriers protecting the diversion channel, and for the first time
in history, the course of the great river was altered by man .
The High Dam was completed in 1971, and since then the
water contained by it has reached a height of 597 feet above sea level, 200
feet higher than the old Aswan Dam . The construction of the new dam was
comparatively straightforward . On the east bank of the river a deep diversion
channel was cut through the solid rock . This led to six intake tunnels through
which 14,000 cubic yards of water pass every second to the biggest
hydro-electric power station in the world and thence to irrigate the old and
reclaimed land of Egypt . The dynamos produce 10,000 million kilowatt hours,
double the previous supply .
Once the Nile was diverted, its old bed was closed
with a rock-fill dam . Rocks cut from the diversion channel were heaped in two
rows across the bed about a thousand yards apart and the space in between was
filled with desert sand, pumped in a slurry of water from huge deposits in the
area . Buried in this sand were large concrete inspection tunnels and down the
centre a vast curtain of concrete descended into the granite bedrock to prevent
seepage of water through the sand and rock-fill . Once the water had drained
away from the sand it was compacted by heavy mechanical rollers or cylinders
which gave it a consistency approaching sandstone . Additional strength was
provided by injecting cement under great pressure into the natural crevices and
flaws in the surrounding rock ; this was especially necessary in the diversion
channel area . The width of the High Dam is 1,070 yards at its base and 45
yards at its crest . It is 4,000 yards long and 120 yards high . This huge
construction contains the equivalent in material of seventeen pyramids the size
of The Great Pyramid of Cheops ( Khufu ) . Enough metal has been used in the
gates, sluices and power plant to build 15 Eiffel Towers . As the Egyptian
workmen rightly sang, " We built the pyramids, we will build the Saad-el-Aali
" .
The great advantage of the High Dam is that it can
store surplus water over a period of years, thus balancing low floods with
high, something that would have temptation greatly to King Djoser . It will
give two million extra acres of arable land to Egypt and five million to the
Sudan . This irrigation will not be seasonal as in the case of the Aswan Dam,
but will be continuous throughout the year and every year, thus providing
additional cropping . Against these gains is the loss of the valuable silt
which will now sink to the bottom of the lake and at most increase the
freshwater vegetation for the benefit of the excellent Nile fish . It is
estimated that in some five centuries' time the silt will fill up the lake, but
perhaps by then some other means of water conservation may have become
available or the climate of the country may have changed back to its lush
pre-desert state . Already the evaporation from the two thousand square miles
of lake surface, reached at 7 per cent and representing 6,200 million cubic
yards annually, has caused unusual clouds and haze in the surrounding area .
The absence of silt in the lake will cause the water to lose its famous eau-de-Nil colour and become blue .
Whilst the High Dam was one answer to Egypt's problem
of feeding her ever-growing population, it presented a very grave threat to the
existence of Philae, the only temple complex between the two dams . The temples
were caught in the artificial lake between the dams and kept permanently in an
almost submerged position . Much worse, they were subjected to a daily rise and
fall of several yards . This tidal movement will lead inevitably to the erosion
and destruction of the temples . If Philae were to be preserved, international
action was necessary fast .
Between 1959 and 1968 consideration was given to a
number of plans for saving the temples . Two schemes merited special attention
. The first, proposed by the Egyptian engineer Osman Rostem, was supported by
the government of the Netherlands . This plan was to isolate the island from
the rest of the reservoir by a series of small dams linking the islands of
Bigeh and Agilkia with the bank of the Nile to form a protective barrier behind
which Philae could rest in a lake of her own, where the height of the water
could be maintained at the most suitable level . This scheme, like the similar
French one for Abu Simbel, was finally rejected in favour of the present
project, which is to transfer the monuments stone by stone to the nearby island
of Agilkia . There they will be re-erected in positions similar to those they
previously occupied, but on a site safe above the new water level .
Philae and Abu Simbel were the most important temples
to be threatened by the High Dam, but many monuments, villages and cemeteries
have been affected by the rising waters, which now stretch southwards for over
300 miles - as we mentioned before - and form a lake with an average width of
eight miles and a depth of 100 feet . Some of the ancient ruins have been saved
by UNESCO and great efforts have been made by archaeologists from all over the
world to excavate and determine the sites before they were covered . Much
useful information was obtained in the short time at their disposal . The work
was greatly encouraged by the government of Egypt, which allowed a part of the
excavated material to be kept by the participating countries . Some of these
rewards were more scientific than artistic .
The work at Philae was subject to all the problems and
difficulties which beset great operations of this kind and is being carried out
by the UNESCO Executive Committee of the International Campaign to save the
Monuments of Nubia . Perhaps the most daunting task confronting the Committee
was the raising of the necessary finance to pay the project's cost . This was
again greatly helped by the government of Egypt's offer of antiquities to the
forty-four States which participated in the preservation of the ancient
monuments . Italy, the Netherlands, Spain and the U.S.A. each received a
temple, Debod being allocated to Spain where it is to be re-erected in Madrid, Dendur
was given to the United States, Tafa to the Netherlands, and the chapels of
Ellesyia to Italy . Smaller antiquities going to other States will be shown in
their respective museums .
Many appeals had to be made before the world
recognized the value of saving these treasures, but eventually widely differing
countries provided money to enable the work of salvage to go ahead . At UNESCO
headquarters in Paris a group of international experts assembled to consider
measures for preserving not only Philae but other treasures of the world's
cultural and natural heritage . The result of their meetings is that the rescue
of Philae is being carried out by Egyptian engineers assisted by Swedish,
French, German and British consultants . The cost will come to some £7½
million, of which a magnificent £650,000 was raised by the Exhibition of the
Treasures of Tutankhamun at the British Museum . The young king has been a
great origin to the preservation of his ancient kingdom as well as a splendid
ambassador for Egypt . The Treasures of Tutankhamun have already been to the
United States and Japan and will also be seen in Russia before returning to the
United States to be shown in New York . The Egyptian authorities responsible
for the saving of Philae are H. E. Dr. Gamal Moukhtar, Vice-Minister of
Culture, Mr. Ahmed Kadri, Director-General of the Organization for the Preservation
of Nubian Monuments, and Dr. William Selim Hanna, the chief engineer . As René Maheu, the Director-General of UNESCO, has said
: " By positive awareness of a universal cultural heritage, mankind
recognizes its own oneness in time and space, and proclaims the unity of its
destiny through the centuries and the nations " .
The contractors for the saving of Philae are the High
Dam Authority and the Italian group Condotte d'Acqua and Mazzi . The High Dam
Authority is responsible for the construction of the coffer dam and pumping out
the water inside the dam . It will also prepare the re-erection site on the
island of Agilkia that will have it suitably landscaped . These operations will
cost approximately £2½ million . The two Italian companies are responsible for
dismantling the monuments, transporting them to the new site and re-erecting
them .
Agilkia is a granitic island 500 yards north-west of
Philae . Here 340,000 cubic yards of rock have been blasted from the top and
tipped down its eastern side to extend the available surface and to give the
island the approximate shape of Philae . Bulldozers will level the surface so
that the monuments and temples may be re-erected in similar positions relative
to those they occupied on Philae .
In March 1972 work was started on building the coffer
dam round the island with length of 815 meter; this was the most difficult part
of the operation . It took two years to enclose the island with a double row of
3315 interlocking steel sheet piles, each fifty feet long, had to be driven
through mud and silt until they reached the rock bottom of the river . The thin
corridor between them then had to be filled with 82000 cubic metres of sand,
which fortunately is situated in vast accumulations only three miles away .
Some of the sand was carried by barges and the resulting slurry pumped through
pipes to the site . Here it was directed into the twenty-foot space between the
double row of sheet piles . The water leaked through the narrow breaks of the
piles leaving most of the sand in position . This gift of sand from the sea has
been of enormous value to modern as well as to Ancient Egypt . But the gifts of
the sea and of the Nile would have been of little value if the Egyptians and
Nubians had not toiled to make use of them . The strange nature of the country
and its dominant river had long accustomed them to short bouts of excessively
hard work . In the little Nubian villages, the only time available for crop
planting was between inundations when for a short three months strips of land
would appear in the bed of the river as the water receded . During this time,
the industrious Nubians had to sow and harvest their scanty crops . The
escarpments on which their villages stood were too high to be flooded by the
river and, apart from a few carefully irrigated and built-up fields, all was
desert . The building of the High Dam and the rescue of Abu Simbel, Philae and
the other temples would have been impossible without their hard-working
co-operation .
Once the sand was properly compacted in the coffer
dam, the pumps which served to pump the sand and water slurry were used to
drain the temples . The water was reduced by about ten inches a day until the
island was clear of the Nile water for the first time since the High Dam was
built . When the temples emerged they dried out in the hot sun and the accumulations
of mud and algae were carefully brushed off so that the carvings and
inscriptions could be recorded by photogrammetry . This is a photographic
process the produces an accurate picture in depth of the subject and enables
exact reproductions to be made if such necessity occurs . Once this is safely
completed the temples will be dismantled . As in Abu Simbel every piece of
stone will be marked and numbered so that it can be replaced in exactly the
same position in relation to its fellows when it comes to be reassembled . The
upper stones will naturally have to be removed first and carefully placed in
order to await the removal of all the stones, including the foundations . Once
the foundation stones are re-laid on their new site on Agilkia the rebuilding
of the temple will continue until all the stones are accurately re-sited . The
deviation from the old positions is unlikely to be greater than a tenth of an
inch, which was the condition laid down for the operation at Abu Simbel, a more
difficult situation since the temples had to be cut out of the living rock from
which they were originally carved .
Such a mission is not without problems . Finance and
time are of the utmost importance ; anything which slows up the work increases
the cost . The programme was running late, due to the lack of power in the
early stages for the planned hydraulic filling of the coffer dam . Instead work
was started with two groups of excavators and lorries delivering sand to a
temporary harbour close to Philae . In this harbour the sand was loaded on to
self-dumping barges for transport to the coffer dam, where the cargo was
released between the two rows of piles . Recent borings on the proposed
coffer-dam line have shown that a change in the line is necessary south of Trajan's
Kiosk . This change will result in an increase in the total length of the
coffer dam, but it may be possible to use a single row of sheet piles for the
modified alignment . If so the available piles would be sufficient for the
extra length, but the sand-filling will increase by about 140,000 cubic yards .
Some of the pumps for draining the site have not been
used since the High Dam was completed and will require overhaul before draining
commences . At first the pumps will be kept near the surface and lowered as the
water level falls, and towards the end they will have to be installed in
specially dug deep wells . With this type of coffer dam leakage through the
sand is likely to be greater in the initial stages before the sand is fully
compacted, and as it is extremely difficult to forecast how many pumps will be
required to overcome the leakage it is necessary to calculate this on the safe
side . In addition a reliable power supply is essential, and although the main
supply will come from the High Dam distribution system, diesel generators
should be on the spot to stand by for any emergency . Should the pumps fail for
any reason during the dismantling of the temples they would once more be
covered with muddy water and all the hard work would have to begin again with
the attendant difficulty of raising the extra finance . The construction of the
coffer dam and the draining of the site are the most important and most
difficult of all the work required for the salvaging of the monuments of
Philae, but – all being well – the temples should be safely on their new site
by the end of 1976, and landscaping, which will cost some £250,000 and require
thousands of tons of fertile silt, should be completed in 1977 .
Like the temples of Abu Simbel the temples of Philae
were made to last for eternity . We mortals of this anxious and uncertain age
may well wonder if the work of our time is destined to last as long as theirs .
To be
continued ....
Part ( 5 ) .. Coming SoOoOon .....
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