The Ancient Dams Built by the Timurids (1350 to 1490 A.D.) in North East of Iran

The ancient dams built by the Timurids (1350 to 1490 A.D.) in North East of Iran

Abbas Kangi 1, Jafar Rahnamarad 2,* , Mohammadali Alizade 1, Ahmad Ghandehary 3

1Department of Geology, Shahrood Branch, Islamic Azad University, Shahrood, Iran 2Department of Geology, Zahedan Branch, Islamic Azad University, Zahedan, Iran 3Office Manager of Basic Studies of Water Resource, Khorasan Razavi Regional Water Co

Abstract: Large reservoir dams of the Timurid era (1350 to 1490 A.D.) in Khorasan province can best display the great ability of Iranian engineers and architects in constructing large water structures. In the first half of the period, two gravity dams of Golestan and Fariman were also built in a similar style and now after 600 years they still stand strong and continue to function. In the second period of the Timurid era, engineers took a daring step by changing the design and building buttress dams of Torogh and Baisonghor (Akhlamad). Employment of multi-purpose structures in these dams marked a major development in the science of dam building. Building water diversion galleries in the dam's body, Bell-Mouth spillway make and Penstock through spillway walls are among the innovations of the engineers of this period. These large water structures indicate the great knowledge and skill of the engineers of the period in dam building. Unfortunately, due the poor quality of the existing materials at that time, construction of some of these dams failed. These engineers thought far ahead of their time and created designs that can still be seen in modern dams after 500 years.

Key words: Ancient Iranian dams; Timurid era; Gravity dams; Bell-Mouth spillway

1. Introduction dams posed the problems of making the dam's body watertight, devising a water diversion mechanism *Water shortage in Iranian plateau multiplies the for the building phase and a spillway system. At that value of this vital element. Consequently, this time, engineers came up with interesting solutions. country has always strived to achieve and reservoirs Furthermore, building each of these structures faced water. Throughout the several thousand year old problems which were resolved in the later projects. history of Iran, water has always played a key role. Arc dams of Kabar and Kart, gravity dams of Saveh, Discovery of the remnants of water structure such as Golestan and Fariman and buttress dams of Torogh dams, cisterns, water channels and wastewater and Baisonghor represent the innovative and systems and others are indicative of the intelligent intelligent efforts made in building weirs. The three use of water resources by ancient Iranians (Kuros essential factors of site selection, the condition of the and Labbaf, 2007). foundation and employing suitable materials were The effort that Iranians have put into exploiting considered in most of these dams. water resources is dividable into two main periods. Through their innovations in building reservoir The first period from 1000 B.C. to the end of the dams, the engineers of the Timurid era have Sassanid dynasty in 600 A.D. In this period, Iranians undoubtedly brought into existence the most started to build diversion weirs in to control surface flourishing dam-building period of ancient Iran. The water. Among these structures one can mention magnificent design and architecture of the Timurid weirs such as Daryoush, Bahman, Shahpur, Mizan monuments has influenced a major part of Central and Amir that date back to 2000 to 2500 years ago in Asia, from Turkey to India. Years after the extinction south west of Iran (Kuros and Labbaf, 2007). All of of this dynasty, the plan and design of the Timurid these structures are weir bridges and are built with constructions were employed in other countries in the purpose of bridging and diverting water. There similar buildings (Allan and Metalwork, 1989). are channels inside these weirs which carry the The present study investigates the dams of water to the mills. Golestan, Fariman, Baisonghor and Torogh in terms The second period of dam building in Iran started of engineering characteristics, material type, from 1100 to 1620 A.D. In this period, designing and constructing conditions and the problems that occur building dams underwent a significant after reservoir water. Due to lack of historical transformation. In a way that for the first time evidence regarding the construction stages and engineers and architects started to build large dams operation of the dams, all the results presented here for the purpose of reservoir water. Building such are based on field studies, drilling results conducted on the body of the dams and eventually comparison of the results with current methods of operation. * Corresponding Author.

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2. History of dam construction in Khorasan Golestan dam was contemporary to Goharshad mosque (1395 to 1399 A.D.). Some believe that Numerous spoils and the vast lands that came Khatoon Goharshad named this dam after her along with the conquest of India, allowed the bondwoman, Golestan (Fadai, 1996). Therefore, Timurid the necessary resources and tools to display probably Golestan dam was constructed their glory and grandeur in the form of their contemporary to Shahrukh, the second Timurid king, magnificent monuments, and for this purpose they and Goharshad mosque. Furthermore, the employed art and engineering (Blair and Bloom, similarities between Golestan and Fariman dams in 1993). They gathered all the great artists, architects terms of design, geometry, material type, brick and engineers from all the countries under their dimensions and brick laying style indicates their dominion to Samarkand, the center of their contemporariness. Considering the government. In the Timurid era art, architecture and contemporariness of Golestan and Fariman dams engineering flourished in the center of their and Goharshad mosque, perhaps Qavam al-Din government, Khorasan (Allan and Metalwork, 1989). Shirazi and Ghias al-Din Shirazi, the most famous After Timur's death, his son, Shahrukh, came to architects of that time, played a major role in the power. In his reign (1386 to 1429 A.D.) he erected construction of these two dams. magnificent monuments around the sanctuary of Due to its inability to reservoir water and Imam Reza in Mashhad. In other words, most of the destruction of parts of the spillways and water structures of Timurid era in Mashhad and the transmission galleries, Baisonghor dams is neglected surrounding areas were built during the reign of by historical documents. The only remaining Shahrukh and his art lover wife, Khatoon Goharshad evidence is the name which in some historical (Allan and Metalwork, 1989). At the request of his documents is mentioned as Baisonghor the son of wife, Shahrukh turned Mashhad into the capital of Shahrukh. During the reign of his father he was the engineering and architectural innovations. At this ruler of western Khorasan. During his rule over time the sanctuary of Imam Reza, as an immensely western Khorasan and his reign (1430 to 1439 A.D.) sacred place, was magnificently reconstructed and he had many contributions to the prosperity of modernized. Goharshad mosque was built adjacent Khorasan province and therefore one can cautiously to the sanctuary at the order of Khatoon Goharshad attribute the construction time of the dam to the (1395 to 1399 A.D.). Presently, Goharshad mosque is reign of Baisonghor. considered one of the most beautiful and glorious Although there are no inscriptions mentioning Islamic monuments. Most of the majestic the construction date of Torogh dam, but most monuments of the first half of the Timurid era were historical texts attribute its construction date to the designed and built by two famous architects, Qavam reign of Sultan Hussein Bin Bayqara's era (1454 to al-Din Shirazi and his apprentice, Ghias al-Din Shirazi 1490 A.D.), last king of Timurid dynasty. In some (Pugachenkov a, 1981). other historical texts, Torogh dam and its water mill The attention Shahrukh devoted to Mashhad are attributed to Alishir Navayi, minister and close resulted in the rapid expansion of the city and its adviser to Sultan Hussein Bin Bayqara and one of the population which in turn increased the need for scientists and scholars of the Timurid era (Molavi, water. Therefore constructing reservoir dams 1963). During his ministry, this competent minister around the city was on the engineers and architects' constructed many monuments and contributed to agenda. The most important dams remaining from the prosperity of Khorasan province (Blair and that period include the four dams of Golestan, Bloom, 1993). Considering the similarity of the Fariman, Baisonghor and Torogh (Fig. 1). No design of Baisonghor and Torogh dams, it seems that inscription has been found in any of these dams to both dams are designed and constructed by one indicate their construction date and therefore there architect. As a result it is possible that Baisonghor are many controversies in this regard. and Torogh dams were designed by the apprentices Correspondences concerning the division of dams' of Qavam al-Din Shirazi and Ghias al-Din Shirazi. It water, ownership of the downstream lands, the seems that these architects collaborated with their material used in the construction, brick laying style, masters in the construction stages of Golestan and the building method and similarities in the design Fariman dams and acquired valuable experiences. In are among the most important documents used in designing Baisonghor and Torogh dams, they didn’t the estimation of the construction dates of these follow the method of their masters and founded a large water structures. In case of Golestan dam, the new style of dam building. most important historical evidence dates back to 550 years ago somewhere between the years 1451 to 3. Saroj mortar 1477 A.D.. In this document Sultan Abu Said Mirza, a king of Timurid dynasty, appointed Molana Qutb al- Resistant and watertight materials are Din Muhammad Khafi as his representative to solve indispensible for reservoir water behind a dam. the water sharing dispute of Golestan dam (Navai, Saroj mortar is one of the innovations of Iranian 1976). Therefore it can be concluded that the architects and was employed before the invention of construction date of Golestan dam must have been concrete. Due to its low permeability, Saroj mortar is before this order. Also in other historical documents used in the structures that are in direct contact with there are indications that the construction date of water such as cisterns, pools, baths and etc. In 68

Kangi et al / WALIA, 31(S1) 2015, Pages: 67-75 addition, it was also used in dams and bridges as the Saroj, but considering the buildings where this mortar used between stone and brick. Building material is employed, one can estimate the history of reservoir dams became widespread at the same time its usage in the Iranian plateau to 900 years ago that Saroj mortar became popular in Iran. Although (Kuros and Labbaf, 2007). we don’t know when exactly architects started to use

Fig. 1: The location of Golestan, Fariman Baisonghor and Torogh dams relative to the city of Mashhad

It is very difficult to make Saroj. It is obtained by Golestan and Fariman dams are gravity dams and mixing lime, clay, sand, ash and water. In the first have pyramidal backside. They almost have identical stage of creating the material, clay and lime are geometrical characteristics. The dams are built with mixed in the ratio of six to four, and by adding water a height of 15m from the river bed, 100 and 130m the initial viscous material is prepared. Then some crest length, 10m crest width and 25m foundation ash, found in bath furnaces, along with some natural width. There are 20 to 22 chambers built on the fibers (a type of straw called Loui) is added to the exterior of the dam which gives a special beauty to mix. Eventually the material is massaged and the whole structure. The pyramidal backside is pressed for 24 hours using a heavy wheel pulled by added to increase the dam’s body strength. A major animals, so that the mixture is completely part of the body of the Golestan and Fariman dams homogenous. Ash contains a lot of non-crystalline are made of rocks and Saroj mortar. In this part, Silica which when combined with lime slush there is a regular network of carved wood, the cross produces calcium silicate, but this chemical reaction section is 10x10cm and it is 6cm long, which is is very slow. Therefore the process of massaging and weaved together. This turns the dam's body into an pressing takes a lot of time. One of the main integrated mass. The wood is covered with a special disadvantages of Saroj mortar is that its volume resin to prevent decay. In order to make the decreases by becoming hard, which usually entails foundation watertight, 2 to 3 meters of the alluvium cracking. The purpose of mixing Loui fibers is to is removed from the base of both dams and it is filled prevent cracking. with rocks and Saroj mortar. Therefore the body of the dam is directly posited on impermeable stones. A 4. Golestan and Fariman Dams harmonious design and use of suitable materials is

Kangi et al / WALIA, 31(S1) 2015, Pages: 67-75 the reason why they still remain strong and stable built with three controllable valves in the left side after 600 years of contact with water. fulcrum of both dams. Much effort has been put into The exterior of both dams are covered with making the added parts similar to the original bricks and Saroj mortar in the form of a beautiful design. Consequently, 22 chambers were added to architecture. The bricks are in two different sizes. the exterior of the dam (Fig. 3). The big bricks are 27cm wide and 40cm long and the length and width of the small ones are 29cm. Both brick types are 6cm thick. There is a well-made of bricks in the middle part of both dams in which penstocks and the sedimentation system are located at different levels. There is a spiral stair case on the periphery of the well which allows access to the valves (Fig. 2). To prevent the destruction of the Penstock, large boulders, called Harkareh, are used. The boulders are made of serpentine, and on the inside they are similar to a carved pipe. The valves can be opened or closed using a gear at the mouth of the intake valves. During all these years most of the Golestan and Fariman dams' reservoir was filled with sediments. Therefore in 1995 the height of Fariman dam was increased by 7 meters. The reservoir capacity of Golestan dam was increased to 5.2 million and Fig. 2: brick well and the stare case of Golestan dam for Fariman's to 3.7 cubic meters (Fadai, 1996). accessing the intake valves Furthermore, two shoot type cement spillways were

Fig. 3: Fariman dam after reconstruction and increasing the height in 1995

5. Baisonghor dam (Akhlamad) capacity: 3 million cubic meters (Fig. 5). The materials used in the construction are bricks and Naturally, new projects can face problems which Saroj mortar. Presently due to the destruction of the in some cases can lead to failure. Baisonghor dam is penstock system and spillways, the dam is not an example of devising new methods of constructing functional. ancient dams. One of the distinctive features of this dam is the spillway and river diversion system. 5.1. Materials used in construction of Baisonghor Although due to the type of the materials used and dam (Akhlamad) construction problems this project was not successful, but it has great value as a new method in The materials used in this dam consist of designing ancient dams. limestone, baked bricks and Saroj mortar. Four Baisonghor buttress dam is located in 66 km horizontal galleries and vertical wells are made of North West of the city of Mashhad and in North East baked bricks and Saroj mortar but a major part of of Iran (Fig. 4). This dam was built in along the the body is made of limestone, 20 to 40cm, and Saroj course of Akhlamad river, crest length: 230m, crest mortar. They are positioned in a way that Saroj width: 11m, base width: 14m, height 12m, reservoir mortar is all around them. Eventually, for

Kangi et al / WALIA, 31(S1) 2015, Pages: 67-75 beautification purposes, thin rocks are skillfully laid diversion system in Baisonghor dam and it was filled on the exterior of the dam. with rocks and Saroj mortar. Then four horizontal galleries were built 20 meters apart. The materials 5.2. Water diversion mechanism used are baked bricks and Saroj mortar. The gallery ceilings are in the form of intersection arched vaults. Two meters of the sediments of the river bed were removed before the application of the water

Fig. 4: Baisonghor dam and accessory structures

Fig. 5: The location of Baisonghor dam and accessory structures on geological map

Each gallery is 1m wide, 2.5m high and 14m long (Fig. 6). In the next stage the course of the river is 5.3 Penstock and Overtopping water mechanism directed into the galleries. Therefore during the process of construction floods could pass through During the construction process Baisonghor dam, these four horizontal galleries. Employing this a vertical well, 2.5m radius, was built on the entry of system of water diversion was an intelligent on the each horizontal gallery which was connected to the part of the engineers of that time. body. These wells were also made of bricks and Saroj mortar. During the building process the connection

Kangi et al / WALIA, 31(S1) 2015, Pages: 67-75 locations between the vertical wells and the diversion system turned into Bell-Mouthed spillways horizontal galleries were open to let floods pass. and penstocks in the operation phase. This Finally in the impoundment phase the connections intelligent design is a significant step in changing the were closed by bricks and Saroj mortar. Therefore construction and operation methods of dams. the four horizontal galleries that acted as a water

Fig. 6: Outlet of gallery number 3 and the application of bricks and rocks in Saroj mortar

There are three water stones in each vertical there is a hole carved with a diameter of 30 cm. At well, with a 30cm internal radius, which are installed the outlet of each water-stone there is a wooden inside the bricks and Saroj mortar. This makes water valve which can be opened or closed by a metal rod withdrawal possible at various levels. These water from the top of the vertical well. In this way the stones are made of Serpentine and were brought to water withdrawal of this dam is carried out through the location from the rock mine of Mashhad which is 12 water stones which are positioned at different 66 km from the dam site. These stones are levels (Fig. 7). cylindrical with a diameter of 50 cm, inside which

Fig. 7: vertical well of the spillway number 2 and the water stones used for water withdrawal

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5.4. Problems of Bell-Mouthed spillways in materials of the time. In other words the design was Baisonghor dam 500 years ahead of its time and therefore its innovation turned into the biggest weakness of the 600 years ago, the designer of Baisonghor dam construction. employed great skill and the existing materials of his time to build a dam which didn’t have any 5.5. Seepage of water under dam foundation and precedence in the history of Iran. In other words, flanks during the long history of dam building in Iran, this dam is the only one which uses Bell-Mouthed Foundation of Baisonghor dam is positioned on spillways. Undoubtedly using Bell-Mouthed 12 to 20 m of coarse alluvial sediments with high spillways in reservoir dams was an intelligent move permeability. Although the dam was not used much, but due to the poor quality of the materials and but water leaks under the body of the dam has implementation problems, this innovative structure washed the sediments under the foundation. turned into its most important weakness. After the Undoubtedly, we continue using the dam the erosion construction the ensuing problems made it difficult of these parts can result in the destruction of the to operate. dam. The flanks are located on Lar formation Baisonghor dam's spillways faced two basic limestone (upper Jurassic). In these limestone problems. First when water entered the system, due sediments, there are Karst cavities along the bedding to the low resistance of the materials (bricks and surface and fractures. Surely these cavities can Saroj) of the spillway area, this area was destroyed. contribute to water seepage. The possibility of the Frequent restorations, using various materials, are contact of water with Lar formation limestone in the indicative of the repetitive destruction of the upper reservoir results in the seepage of water in this part of the spillway tower. Following the destruction section. of the spillway tower during flood times, water entry to the horizontal gallery was increased which 6. Torogh dam resulted in the destruction of the discharge area. If this condition remains unchanged it can cause the Torogh gravity dam is 14 kilometers from South total destruction of the spillway tower and severely of Mashhad and is constructed on Jurassic granite damage the dam. (Fig. 1). The dam is located along the Torogh river The second problem is water leaks from the and its dimensions are as follows: crest length: 60 m, bottom of the vertical wells in the spillway. Low crest width: 7 m, foundation width: 11 m and height: thickness of the bricks (50 cm) and weakness in 20 m. The materials employed in the building of the water tightness of this area causes water leakage structure consist of stone, brick and Saroj mortar. into the horizontal gallery. Therefore water leaks The majority of the body is made mainly of granite gradually increase and destroy the bottom part of boulders and Saroj mortar and on the exterior, brick the spillway well. Recently, a little water has been laying is skillfully employed with the thickness of 1 stored adjacent to the vertical wells which leaks into m in order to strengthen and beautify the structure. the horizontal gallery. Water leakage happens where The materials used for brick laying are baked bricks bricks and mortar join. This weakness resulted in the and Saroj mortar (Fig. 8). gradual water leakage and destruction of the bottom Designing and building of Torogh dam was done part of the spillway number 1 in the left side fulcrum years after the construction of Baisonghor dam and during the last impoundment (Fig. 4). The therefore many of the problems that manifested in destruction of the connection point between the the case of Baisonghor dam were correct in this new vertical well of the spillway and the horizontal structure. The only differences between the two discharge gallery has resulted in the severe erosion dams are the dimensions of the body, width of the of the river bed sediments in the outlet of the gallery river and the corrective measures taken in response number 1. to the initial weaknesses of Baisonghor dam. In the This innovation in the structure of reservoir case of Torogh dam, three meters of the sediments of dams was a courageous act by the architect. In the the river bed are removed and the body is posited new method the problem of water diversion during directly of the granite rocks in order to make the the long period of dam construction is rectified. In foundation watertight. After filling the river bed with the final phase of the construction the spillway boulders and Saroj mortar, an 11 m long horizontal system and penstocks are connected to the gallery is built. The gallery is built using baked bricks horizontal galleries. But in flood times Saroj mortar and Saroj. was rapidly destroyed and caused serious damage. The ceiling is in the form of arched vaults. The At this point the connection between the well of the gallery is 1 m wide, 3 m high and 11 m long. During spillway and the horizontal gallery and the outlet of the process of the construction of the dam, the river the gallery was severely damaged. These damages is directed into the horizontal gallery and therefore rendered the dam nonfunctional and the project water can during floods. During the construction failed. In spite of the intelligent design devised by the process, an intake tower is built connected to the architect, it was not possible using the inferior 73

Kangi et al / WALIA, 31(S1) 2015, Pages: 67-75 body, 6 m diameter, at the entrance of the horizontal which pours the overflow of water in the middle and gallery using bricks and Saroj mortar. Inside this lower parts. intake tower there is a well with 1.5 m diameter. There is a big hatch on the upper part of the tower

Fig. 8: Torogh dam and accessory structures

There are 4 small penstocks for water intake at different levels. There are transverse beams in the 7. Conclusion well in the form of a staircase to allow access to the intake hatches. During the construction of the dam, Large reservoir dams of the Timurid era, the connecting point of the intake tower and the Golestan, Fariman, Baisonghor and Torogh, tell the horizontal gallery is open to let floods pass. In the tale of an area when dam building engineering final stage the connection point of the intake tower flourished. Construction of Fariman and Golestan and the horizontal gallery is closed using bricks and dams in the first half of the Timurid era indicates the Saroj mortar. Therefore during the construction mere copying of the design in other similar reservoir phase the horizontal gallery acts as a water diversion dams, but in the second half of the era we can system and during the operation phase it turns into a witness the efforts that engineers and architects put spillway and penstock. The high thickness of the into creating new and innovative designs. One can intake tower has rectified the problem of the lower find many major adjustments in these structures, parts of the tower being damaged in the previous aimed to cut costs and fix the many constructional case. and operational problems. These intelligent If we are to make a comparison, the location of modifications were valuable experiences in dam Torogh dam is better than Baisonghor dam. building engineering. Although some parts of the Generally, the low river’s width, low thickness of the spillway system and penstocks of Baisonghor dam sediments and fewer numbers of floods in Torogh were damaged after the first impoundment attempt river furnish a better condition for Torogh dam. but it is an excellent and intelligent effort put into It has been 600 years since the construction of creating a unique construction. Undoubtedly, lack of Torogh dam and it is still standing strong. The proper materials, such as concrete, were the greatest reservoir has been dredged several and times the restraint on the engineers who contemplated dam has been used up to the first half of the innovative ideas. but the modifications made on twentieth century. In 1981, the construction of the Torogh dam is suggestive of the gradual growth of Torogh concrete arch dam with the height of 60 m dam building technology in this era. commenced. This dam is located in the distance of 500 m from the old dam. For the purpose of References transferring water to the new dam, a tunnel was dug with 4 m diameter in the body of the old dam. Kuros, GR., Labbaf, K.M., 2007. Water and irrigation Unfortunately this tunnel has completely destroyed a techniques in ancient Iran. Iranian National major part of the old structure including the water Committee on Irrigation and Drainage (IRNCID). diversion horizontal gallery. P. 199.

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