Kowie River Wagon Bridge - Henry Putt Bridge
People:FW WALDRON: Engineer
KNIGHT and FOLKESTAD: Contractor
Named after Henry PUTT, manager of the Kowie Railway.
This Bridge at Port Alfred, for which FW WALDRON appears to be the primarily responsible engineer, comprised nine spans of 9,0 m each constructed of reinforced concrete supported on abutments and piers, these in turn supported on reinforced concrete piles. It is thus the first designed reinforced concrete structure in South Africa. The design of this bridge, in essence a series of continuous girders supported on piles, would have been considered daring at the time if executed in steel, in reinforced concrete it was considered shear lunacy! It was then some £1 400 [R2 800 before escalation] cheaper on tender than its equivalent in steel and sounded a clarion call for the use of the material in civil construction in South Africa and as such is an historic landmark. WALDRON presented the design in 1907 to the Cape Society of Civil Engineers.
The bridge was replaced by a dual carriageway bridge built alongside in 1928 and then both bridges were demolished and replaced by the current Putt Bridge in 1989 next to which a memorial was built in 2001.
(Paraphrased from Fredman 1964:36)
The Henry PUTT Bridge, Port Alfred.
The laying of the foundation stone of the Henry Putt Bridge by Sir Walter F. Hely Hutchinson on 1 September 1906 represented a great advance for reinforced concrete in southern Africa as this was the first reinforced concrete bridge built in this country.
In his speech at the opening of the bridge on 15 September 1908, the Hon. Mr. D. P. de Villiers Graaff said: "The bridge has been constructed by the use of reinforced concrete and is the first of its kind in the Cape Colony. It may be said to be on trial, but every confidence is placed in its reliability." Mr. de Villiers Graaff went on to say that he believed the system of reinforced concrete had a great future before it.
After the change in the configuration of the river brought about by the harbour works which commenced in 1840, there were no drifts across the Kowie River in the vicinity of Port Alfred. For 32 years before the opening of the bridge the two halves of the town were linked by a pont which plied the river just below the site of the bridge.
It seems that the construction of a bridge had been contemplated for eight or nine years before the foundation stone was actually laid. One assumes that Mr. Henry PUTT, after whom the bridge was named and who was manager of the Kowie Railway for more than 26 years and Mayor for 21 years, must have played a major part in its planning.
The bridge itself carries a single carriageway on four beams 900 mm deep over nine spans of approximately 9 m without any expansion joints. The piers are slim and rather elaborate concrete lattice work while the handrail was an ornate system of panels with wheels and St. Andrews crosses between the uprights. During the 1940's the panels were filled in and plastered over so that no trace of the original work remains.
By the mid-1920's traffic had increased and the bridge had deteriorated to some extent so that loads had to be restricted. It was therefore decided to construct a new double carriageway bridge of the same span immediately downstream of the Henry Putt bridge. This bridge was completed in 1928 and is still in use today while the Henry Putt bridge is used only for pedestrian traffic.
The bridge is almost 2 km from the sea but on the seaward side the concrete has been badly affected by corrosion of the reinforcing steel and most of the steel is exposed. It is possible that the concrete was not very dense but the main cause of the damage is that the cover is only about 10 mm thick in places. Attempts have been made to repair the piers by casting blocks of concrete around the affected sections so as to increase the cover to 50 mm, but this additional cover has also spalled off due to continuing corrosion of the steel.
The lesson of the Henry Putt bridge was not lost upon the designer of the replacement bridge as this bridge, which was built more than 50 years ago, shows no sign of damage due to corrosion.
An inscription on the foundation stone of the Henry Putt bridge indicates that the bridge was designed by the Department of Public Works under the supervision of Mr. F. W. WALDRON, AMICE, and that the Chief Engineer was Mr. W. CRAIG, AMICE.
The contractors were Messrs KNIGHT and FOLKESTAD and the Clerk of Works, Mr. W. PURSE. It was Mr. WALDRON's last job for the Cape Government before he retired from the service and entered into private practice in Cape Town.
The bridge, which took two years and one week to construct, cost £6 400 and supervision a further £450. This was apparently considered a very low cost as, to quote once more from Mr. de Villiers Graaff's remarks on reinforced concrete: 'We might be allowed to draw attention to the advantages and suitability for its adoption elsewhere throughout the Colony on account of its cheapness (only 2/3 of the cost of an iron structure), durability and graceful appearance.'
The festivities accompanying the opening of the bridge seem to have warranted a public holiday. Several pages of current issues of Grocotts Penny Mail and the Grahams Town Journal were taken up with descriptions of the event. Members of the Port Alfred Gymnastic Club gave a polished display, ladies and gentlemen sang and pianoforte duets were played.
The major event was the Ball which is described in minute detail in the newspapers. We can only regret that nothing like the same celebrations took place when the Nico Malan bridge 500 m downstream was opened. The fate of the Henry Putt Bridge is still undecided. It is quite incapable of carrying modem traffic but serves a very useful purpose as a pedestrian bridge carrying up to 5 000 persons per day, thus diverting the pedestrian traffic from the other bridge which could not accommodate them safely. The bridge is, however, deteriorating rapidly and it has reached a stage where a decision must be taken as to whether the bridge is to be repaired or demolished.
Demolition of the bridge and complete removal of the piers, so that they would not be a hazard to river traffic, would be expensive and the probable cost of repairing the bridge is being examined. It is to be hoped that repair of the bridge will prove economic so that one of the most significant advances in the use of reinforced concrete in this country will be preserved.
SOURCE: Looking Back, December 1982
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