A CASE STUDY ON CONSERVATION OF HERITAGE STRUCTURE OF DANISH FORT AT TRANQUEBAR VILLAGE, TAMILNADU, INDIA

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1 International Journal of Civil Engineering and Technology (IJCIET) Volume 8, Issue 6, June 2017, pp , Article ID: IJCIET_08_06_082 Available online at ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed A CASE STUDY ON CONSERVATION OF HERITAGE STRUCTURE OF DANISH FORT AT TRANQUEBAR VILLAGE, TAMILNADU, INDIA N. Rajesh Research Scholar, Veltech Technical University, Tamilnadu, India S.Suppiah Professor, Department of Civil Engineering, Veltech Technical University, Tamilnadu, India P.Purushothaman Professor & Specialist Civil Engineer, DDM Engineers, Chennai, Tamilnadu, India ABSTRACT Danish Fort at Tranquebar village at Tamilnadu, India is a 400 year old heritage structure built in the year 1620AD, using country bricks and lime mortar on the sea shore of Bay of Bengal, which is affected by cyclones every year. The structure has been in constant use and disuse in the past, and major rehabilitation and serious conservation works have been carried out since This paper brings out the brief history of the structure and the conservation efforts made in the past and recommend further research required to extend the life of the structure and further transfer knowledge of lessons learnt to conserve similar buildings. Even today bricks are used in large quantities in residential and commercial buildings and if the life of the structure could be enhanced, that would have high favorable impact on environment in terms of reducing quarrying of clayey earth, sand, lime stone and cutting of woods which are used in making of bricks and lime or cement mortar, which are used in buildings. Key words: Heritage Structure, Country Bricks, Lime, Conservation, Environment, Enhancing Life of Structures Cite this Article: N.Rajesh, S.Suppiah and P.Purushothaman, A Case Study on Conservation of Heritage Structure of Danish Fort at Tranquebar Village, Tamilnadu, India, International Journal of Civil Engineering and Technology, 8(6), 2017, pp editor@iaeme.com

2 N.Rajesh, S.Suppiah and P.Purushothaman 1. INTRODUCTION The Danish fort, called, DANS BORG Castle is situated at Tranquebar village on sea shore of Bay of Bengal. The site is located at coordinate N, E about 300 KM from Chennai. This fort was built in the year 1620 by Danish, later army barrack was constructed in the year 1780; renovation was done in the year The fort changed hands from Danish to British. After independence, the state Public Works Department was using it as an inspection Bungalow, then Tamilnadu State Department of Archeology (TNSDA) took over the preservation of the monument in the year 1977 and a museum was established in the year 1979[1,2,3]. Major materials used in the construction of the structure were local burnt clay bricks, lime sand mortar with traditional technology prevailing in those days some 400 years before. The area is famous with lots of temples built in stone and bricks, still majority of mason hail from this locality that is Thanjavur, Nagapatinam and Trichy districts of Tamilandu. The structure has withstood for such a long period the travails of natural forces and human factors. The location is prone for frequent cyclonic wind force and high sea tides and on one side salty backwater flows inundating the surrounding. The various inspections carried out [4] since conservation was taken over found major issues of falling of plaster, exposure of bricks, loss of joint mortar, dampness, discoloration, rusting of rods, rutting of wooden doors and windows, organic growth, loss of strength of vaulted brick roofs, their toes, pillars, cracks in many places, separation of a portion of brick wall foundation on the outer wall, dampness and leakages in roof and other places. The reports did highlight mis-use in overloading of floors with new constructions, marring original appearance and character by locating toilets, water tanks and septic tanks at in-appropriate locations. The reports also highlight the need to suitably provisioning as the building was converted as a museum and permitting national and international tourists and visitors, requiring housing of artifacts, electrical lightings and fittings, easy movement of differently-abled persons. The inspection experts report that the structure was saved from its collapse by suitable intervention in the last decade, however, on date during 2014, it needs total revamping by undertaking major conservation and restoration in all respect, particularly in strengthening the brick core wall. In this context, this paper attempts to find out the future needs of conserving this structure and identifying items of work which worked well and which requiring further study and investigation. 2. EXPERTS RECOMMENDATIONS FOR FURTHER INVESTIGATION AND WORK. The experts have recommended for further investigation and conservation work mainly based on visual inspection and by their long-standing experience. They have assessed major structural integrity by general good appearance, except in places where damages are evident through age and weathering. They have noted wherever plaster has gone, the core is affected and where ever plaster is still holding, gave the opinion that actual damage to the core could be assessed only after de-plastering. They also have noted that in some places original lime plaster has been replaced by cement plaster and recommend to use pure lime available from particular place called Pollachi. They observe that original floor level at basement had been raised by sand filling, reason for which is not known, could be investigated. The original drainage system could not be identified and dampness in many places could not be explained, which requires investigation and suitable clearing of original drains r new arrangements. They have drawn special attention on the four rectangular dome high roof which were provided with tie rods, which may collapse as cracks, water leaks and dampness are seen, which require proper investigation and intervention. The exact details of the foundation are not known, editor@iaeme.com

3 A Case Study on Conservation of Heritage Structure of Danish Fort at Tranquebar Village, Tamilnadu, India particularly at a location where a portion of a wall has fallen, The expert team has recommended to conduct a trial trench at a safe location to investigate the step footing provided for the structure. They have recommended to use old bricks as recovered close by and re-use, and use either combination lime-cement sand mortar or traditional lime sand mortar. They have also recommended to remove additional dead load above arch work after examination and with due water proofing later after removal of dead load. The experts recommend proper documentation of the studies, recommendations and interventions so that documents will be useful to plan further studies, interventions including critical observations from various expert groups. 3. SUCCESSFUL INTERVENTIONS Traditional mason who are skilled in traditional brick masonry and plaster works are still available, and the materials are also locally available, therefore carrying out the plaster patch works was very successful. The photos show before (figure-1) and after (figure-2) of re-plastering and painting works of basement entrance. Figure 1 Before re-plastering basement entrance The basement floor dampness is still a major issue to be addressed. The reason for raised floor level is also not known, which requires proper investigation. Figure 2 After re-plastering, entrance to basement The photos show before (figure-3) and after (figure-4) of roof plastering with water proofing of the four rectangular domes at high roof. As domes are smaller in size and no access provided, and as no heavy loads coming on to them, surfaces were cleaned of loose particles, plaster, re-plastered with water proofing with proper roof rain water drainage. However, fan hooks/rods hanging from the domes were removed as instructed by the experts. This also indicates proper training of technical persons in planning and carrying out of conservation works of heritage buildings. Model studies are required as dome size and loading increase editor@iaeme.com

4 N.Rajesh, S.Suppiah and P.Purushothaman Figure 3 Before re-plastering and water proofing Figure 4 After re-plastering and water proofing The following photos show shore protection and wave protection from high sea waves. They show before (fig-5) and after (fig-6) re-plastering conservation work. Figure 5 Before re-plastering work, sea side view Figure 6 After re-plastering work, sea side view editor@iaeme.com

5 A Case Study on Conservation of Heritage Structure of Danish Fort at Tranquebar Village, Tamilnadu, India 4. DISCUSSIONS Natarajan e. al. [5] who carried out rehabilitation of St. Lourdes Church at Tiruchirapalli which was built about 280 years later to Danish Fort observe that local materials bricks and lime mortars were used in the restoration work, which enabled bringing back the ancient glory and recommend complete water proofing of roof vaults plaster surfaces and to reduce water related deterioration of heritage structures to enhance functional life these buildings. Central Public Works Department (CPWD), Guide [6] specifies re-pointing of mortar joints in masonry structure once in every fifty years and notes moisture is the key agent in bringing deteriorations in heritage buildings. The hostile coastal environment below surface and above surface is very critical in the maintenance of the structure, which demand careful study on the structural core brickwork right from foundation upto roof including other structural elements, a scientific systematic investigation is required to be carried out before any repair work is taken up. This may also involve non-destructive tests to assess the strength characteristics of structural elements in the structure, particularly the foundation, walls, pillars, vault roof elements. Model studies simulating various environmental factors and loading conditions may also required to be carried out as to compare present conditions and performance as Natrajan et al [5] observe that the modern formal analysis and design facilities were not available in those ancient periods. Sayali and Rohan [7] adopted a systematic approach and nondestructive testing methods to assess structural conditions in rehabilitation of an ancient building at Pune which was built about 250 years later to the Danish Fort and they recommend preventive intervention is best cure to arrest decay of heritage structures. The CPWD guide [6] notes diagnostic studies as doctors do before carrying out rehabilitation. Traditional lime sand mortar characterization studies were made by Kerstin et. al [8] and Thirumalini et al [9] and similar studies together with characterization of bricks used and available in the locality can be done for the Danish Fort. These studies and systematic scientific approach will help to plan future interventions in more professional way and make the structure to stand and serve long. 5 CONCLUSIONS The Danish Fort, a 400 year old structure was brought back to life by the timely intervention by current conservation techniques and the structure is now housing a museum and many tourists national and international visit. The structure is located at very severe coastal environment which require constant vigil and scientific approach to assess present and future conditions through non-destructive testing, model studies of structural elements, characterization of major construction materials used such as in-situ bricks, lime sand mortar, further studies and suitable interventions are required towards checking and controlling dampness. Increasing life of such brick structures will help to design and construct modern residential and commercial structures with more design life, thus reducing environmental impact on quarrying of natural resources and cutting trees. REFERENCES [1] DANS BORG CASTLE at Tranquebar in Nagapatinam District, Tamilnadu, Tourists Information Handout, Tamilandu State Department of Archeology, 2016 [2] The Danish Tranquebar Association, Ideas and Projects, [3] Tranquebar, Under Danish Rule , The Danish Tranquebar Association, Ideas and Projects, [4] Inspection reports on Danish Fort, Tarangampadi, Tamilandu State Department of Archeology editor@iaeme.com

6 N.Rajesh, S.Suppiah and P.Purushothaman [5] Natarajan., C.; Shen-En Chen; and Mohiuddin Syed., 2010, Rehabilitation and Preservation of the St. Lourdes Church, Tiruchirapalli, Journal of Performance of Constructed Facilities, ASCE, 2010, 24(3), [6] Conservation of Heritage Buildings - A Guide, July, 2013, Directorate General Central Public Works Department, New Delhi [7] Sayali Sandbhor and Rohan Botre, 2013, A systematic approach towards restoration of heritage buildings- a case study, International Journal of Research in Engineering and Technology, 2013, 2(3), [8] Kerstin Elert, Carlos Rodriguez-Navarro, Eduardo Sebastian Pardo, Eric Hansen, Olga Cazalla, 2002, Lime Mortars for the Conservation of Historic Buildings, Studies in Conservation, International Institute for Conservation of Historic and Artistic Works, Vol. 47, No. 1, (2002), pp [9] P. Thirumalini, R. Ravi, S. K. Sekar and M. Nambirajan, 2011, Study on the performance enhancement of lime mortar used in ancient temples and monuments in India, Indian Journal of Science and Technology, Vol. 4 No. 11 (Nov 2011), [10] Ar. Rajni Kumar conservation & Restoration of Heritage Structures: Case of TOMBS of Nakodar and Technology, 8(5), 2017, pp [11] Sunaina Kapoor and Partha Sakha Chakraborty Reinvigorating The Parikrama Circuit of An Ancient Heritage City: Mathura Civil Engineering and Technology 8(5), 2017, pp editor@iaeme.com