Transportation Project of the biggest Hard Rock Tunnel Boring Machine in Georgia
In the history of LS Heavlift - our wholly owned subsidiary company, there have been haulages executed for innovative and first-of-its-kind projects for our country. For us, it has always been a great honor and motivation to contribute by our transportation services to the infrastructural development and economical benevolence of Georgia.
Transportation of the biggest hard-rock Tunnel Boring Machine - TBM is definitely on the list of such projects. It included all possible and conceivable logistical challenges, consequently faced and responded with professionalism and authority by us.
For cutting the 9km tunnel, within the range of the new Kvesheti-Kobi road project, hundreds of parts of Chines CERG Solutions’ TBM were delivered via sea in Poti Port, Georgia, in early 2021.
From there, dismantled pieces of the TBM should have been transported 404km away, in the remote Kazbegi Region (a North-Eastern mountainous part of Georgia), and assembled. Considering the number of pieces, it was assessed that approximately 150 haulage trips would be needed to complete the task. In addition, half of the loads were OOG type, which needed a specific approach and equipment.
In the initial phase of project planning, our team commenced route surveillance and mapping. The whole distance has been split up into 3 stages:
- Stage I - From port to Rikoti Pass (the central part of the country);
- Stage II - From Rikoti Pass to the Valley of Khando;
- and Stage III - From the Valley to its final destination - the village KOBI.
The last part of the route, named as Kobi-Gudauri section, was the toughest one, considering its mountainous terrain and meteorological conditions. The narrow road-span full of sharp corners and steep up-hills made the journey quite challenging. Above all, this fair-weather road is heavily burdened with international transit traffic all around the year and can be jammed anytime in winter, due to extreme weather.
Because of these difficulties of the section that, at the same time, represents the crucial international corridor, its modernization project has been slated, including cutting in hard-rock mountains a 9km tunnel. For that, a huge TBM should be delivered in the area.
At the beginning of the planning, our team had to deal with one of the bridges overpassing the Khando river. The construction of the metal dome bridge was too low to let the oversized cargo pass through it. As a solution, a 400m long gravel detour road was cut bypassing the bridge. Later, this new land also served as a temporary station for our vehicles waiting for suitable weather.
Another equally important task was to get assured that every bridge throughout the whole route could sustain the enormous weights of the loaded trailer trucks. There were about 40 bridges on the course. To check these structures, before the project is begun, one year earlier, our team conducted a test drive on bridges with a weight of 160 gross tons.
Yet obstacle to overcome was an avalanche gallery near ski resort Gudauri. Its narrowness did not allow the widest parts to pass through. Such cargos were 4 units of main circular bearings of the TBM, reaching up to 8m in diameter.
As a solution, our team evaluated that round-shaped details should be placed on trailers at an inclination of 25-degree. In such a position, extra-wide details could be carried through the tunnel without being blocked. However, for maximum security and assurance, LS Heavylift conducted a simulation, designing a full-sized mock-up and a special pad of a trailer that would incline the detail at such angle. The test passage of the mock-up was conducted successfully long before the project began and we were ready to receive cargos.
At the terminal stage of preparations, it was decided to conduct transportation operations in night hours, when the road traffic is relatively shallow and OOG cargo transportation does not pose a threat to international transit. However, if a lightweight car can cover the distance of the Kobi-Gudauri section at most in an hour, our haulers with OOG cargos would need at least 6-7 hours to reach the destination. Extra-wide cargos would occupy the whole span of the hilly road and in case of necessity, no car could bypass it, neither emergency services nor police patrols. It meant that in critical situations, services left on one side could not reach their destination on another side on time. Besides, during operations like this, there’s always a certain risk that the truck can stuck in the middle of the road due to technical malfunction and block the way longer than just a couple of hours.
To eliminate this probability, a special plan was elaborated distributing emergency services equally on both sides, so that an OOG cargo trailer would not be a snag for them anymore. In addition, so-called, “road pockets” have been organized in several places that would allow heavy haulers to temporarily enter in, freeing the way and let the traffic flow.
The very last challenges were the international traffic itself and the characterizingweather conditions of the area. Due to high snow, the roads are often blocked up. Our equipment needs also respective treatment in extreme frosts. For not to delay traffic flow, patrol established transportation time-schedules that should be strictly followed. We had to start the delivery exactly at on indicated time and finish it the same way, not a single minute earlier not a single minute later.
Beginning from January until July 2021, our team step by step, with its high expertise accomplished one of the toughest projects in the company’s history. The Tunnel Boring Machine Transportation has been conducted in a half a year without any single accident and delay.
The fully assembled TBM itself testified the scale of the job. Reaching up to 182m in length, 4900tons in gross weight, and 15.8m diameter in width, this giant was ready to begin the second half of his journey.