Jitin Viaduct,
an Arch over Times

Once with the years passing, Jitin viaduct, an impressing railway construction over the wide valley of the river having the same name, has suffered serious damages, fact leading to the starting off, during the current year, of certain vast restoration works.

The first deposits of mineral coal in the country have been discovered in the Semenic Mountains, and the first coal mines have been opened, between years 1771 - 1778, at Anina, Doman and Secu, from Caras - Severin region. Reason why, in 1847, the Austrian state (which was administrating back then these places) has built the first railways from Romania: Oravita - Bazias, in a length of 62,5 km and it was used for the transport of coal from Danube and further more, up to Austria.
Because in time there have started to be discovered other coal or precious metals deposits, Privileged Company of the State Austrian Railways was starting off, in year 1861, works for the building of a normal railways from Oravita to Anina, although on this section there was a small mountain railway, where the cars were hauled by horses.
Located in the middle of Semenic Mountains, on the east -west direction, Oravita - Anina railway section goes round the mountains from Maidan - Bradisorul de Jos, crossing the Jitin Valley, climbs to Carasova, where there gets closer to Resita, and then smoothly gets down to Anina. As there was natural, its occurrence has automatically imposed the achievement of certain important works of art, so on 33.4 km there have been built 14 tunnels, having a total length of 2.084 km, 10 viaducts, summing up 843 km, sustaining walls of the slopes, on a distance of 9.946 km, and mountain cutting of 21.171 km. From this impressing dowry, we will speak today about Jitin Viaduct.

A nature shield
Built in year 1863, under the authority of MAV (Hungarian Railways), Jitin Viaduct has five openings: a central one, of 34.50 m, and two marginal openings, of 15.80 m. The superstructure of the viaduct is sustained by two bricks vault in full template, of almost 15.80 m the light at each end, and a central metallic deck, of 34 m opening, and the infrastructure is made of two heads and four piles, achieved of quarry stones of limestone.
On the bridge, the railway line has a slope of almost 20% and horizontally describes a route made of circular curve with the range of approximately 114 m above the vaults from the Oravita end, an alignment on the central deck and a circular curve with the range of approximately 109 m above the vaults from Anian end. The viaduct crosses the Valley of Jitin, the difference between the superior level of the track and its thalweg being of almost 35 m.
The materials used at its building were: burned brick - for the vaults from the viaduct ends, steel - for the central deck, limestone, for the masonry of the piles, heads and the tympanum sustaining the broken stone prism of the track above its two ends.
The degradation during the time of the technical state of the viaduct is a natural consequence of its aging, of the climatic conditions influences and, obviously, of the ceaseless exploitation since its putting into operation and up to the present time, the convoys operating at increased axle loads and on linear meter. Time passing, the alternations freezing-thawing have also hall cruel marks on the vaults, achieved of brick masonry, which present serious degradations consisting in the stripping off big sections of the first layer of masonry. The piles, having a height of almost 35 m, being similar to some towers watching over the forest that peacefully lives at their shelter, have suffered degradations at the masonry edge preparations, with a slight tendency of displacement of the quarry stones.
As this situation could endanger the safety of building and, implicitly, of the train traffic on the viaduct, until there will be started off its consolidation there have been taken measures for restricting the traffic speed down to 15 km/h and of the axle load and the linear meter of the convoy, as well as the daily checking of the place, followed by the starting off of the bridge expertise action and the drawing up by the Institute for Railway Design and Study of the project for providing safety to the construction.
The specialists have discovered that the superstructures from the brick vault (2x15.80 m - 2.x 15.80 m) have suffered advanced degradations at the last range of bricks, which has determined the stripping off of certain variable sections from one opening to another from almost 15-20% in the Ist opening, up to 60-70% in the IV opening, especially inside the curve, also favored by the predominant wind direction. Important degradations have also been discovered on the marginal outline of the brick vaults, in the area of the tympanum, achieved of stone masonry.
The investigation of the boring has also confirmed the lack of the bonding mortar in the masonry mass, between the quarry stones from the piles and the head masonry, fact that attest the severe diminishing of the resistance capacity and the stability of these structural elements and, implicitly, of the structure assembly. These findings have been made with respect to the tympanum masonry, which are sustaining the track prism above the vault from the viaduct ends.
As there has been noticed, the degradations were progressively increasing from the first to the last opening, being more serious on the left side of the track (inside the track curve), from where there have been detonated and they were probably due to the predominant wind direction and the different degree of sheltering the structure of the two viaduct ends, the end from Oravita being located in the vicinity of the tunnel exit, at the shelter of the very abrupt rocky slope. The degradation of the brick masonry from the vaults has been also favored by the water infiltration (from the water accumulated in the vats sustaining the track rock prism) occurred due to the malfunction of the water evacuation system, and due to the repeated frosting-thawing process. In the areas where the first layer (inferior, ½ brick thickness) was fallen, there was noticed that the bricks providing the link (weaving) between the other layers were broken.
The solutions proposed by the designer have been submitted for notification to the Historical Monument Department within the Ministry of Culture and Cults (MCC). The specialists within ISPCF, in collaboration with the experts of MCC, have succeeded to harmoniously weave the mastery of the predecessor with the contemporary resourcefulness.
The consolidation works at the resistance structure from the viaduct end towards Anina, developed during the current year between August 1 and September 10, have been stipulated to be executed by respecting the following phases:
- consolidation of the resistance structure of the superstructure;
- the consolidation of the resistance structure of the infrastructure;
- the restoration of the viaduct as a historical monument.
For the consolidation of the superior part of the viaduct there has been stipulated: the demolition of the existing vat and the execution of a structure made of beam-concrete structure continuing with three unequal openings (18.45 m + 19.00 m + 12.45 m) between the tympanum of the existing viaduct. The beam continues to be sustained by the existing infrastructure and it has variable sections, with vute next to the props, so that seen from upstream and downstream, lateral sides remained unchanged. The only altering that occurs on the lateral sides of the viaduct is the one that could be seen on the entire length of the viaduct, at the superior part, a concrete band with the height of 1.30 m at the inside and 1.50 m at the outside.
At the composition of the viaduct superstructure there has been taken into consideration the shape of the plan of the existing construction and the position of the railway path in a circular curve having the range of 109 m. In plan, the continuous beam of reinforced concrete exceeds with 20 cm the edge of the existing masonry and it is made of railway sections in alignment, which are snapping on the props, following the curve. The superstructure props are made of concrete blocks laid on the piles, excepting the last one, the one from Anina, which it is executed in the embankment, at the end of the viaduct.
The consolidation of the resistance structure (the continuous beam) has been performed at the convoy T8.5 according to the STAS 3220/89, so the reinforced concrete structure will take over the convoy loads and will send them to the infrastructures, discharging the vaults.
At the restoration works of the viaduct there has been taken into account the same principle, namely, keeping the current shape of the work, in this respect there are in study phase two solutions: the achievement of certain metallic reinforcement networks fixed in the body of the piles and of the heads through special mortars injections or the injection of the stuffing masonry from the infrastructure body with the same type of mortars in order to rehabilitate the degraded links.
The works from the Anina end have been unfolded by shutting down the sections, once with their finalization, in 45 days of interruption, the train traffic being resumed, on September 17, the current year. During the next year there it is scheduled to be also achieved the consolidation of Oravita end, so the Jitin Viaduct will become what it was once: a real railway work of art.

Oana Branzan