In the begging of the 18th century Balakhna - the Volga town in the Nizhegorodsky province - became a center of shipbuilding. At these shipyards they built strong sea ships - shkoats, which were intended for fish-products and other cargo transportation in the Caspian Sea. Building materials for shkoats were mainly pine- and fir woods and partially Persian oak ('temir-agach') or 'iron-wood'. To strengthen the ship's framing they used iron bolts and treenails. Longitudinal beams with thickness of more than 30 cm and with breadth of 40 cm, which were used for flat bottom planking, were joined together by iron shackles. This technology provided increased firmness and durability of shkoats: they served for 20 - 25 years. The ship was clumsy and crank on the wave. Boards with thickness of 6 - 7 cm were used for her deck. A cabin for a pilot was placed under the quarter-deck and behind the main mast there was a vast kitchen with a Russian stove. The main dimensions of the topsail shkoat were: length - 24.5 - 46 m; breadth - 7 - 11.3 m; hole depth - 3.7 - 5.2 m, draught w/cargo - 3.6 - 4.9 m; cargo capacity - 250 - 500 t. Her crew consisted of 12 - 18 people. There were two or three anchors on the ship with the mass from 400 kg to 1 t. The length of anchor hempen cables was 200 - 250 m. The rudder was moved with the help of the hemp by means of hemp tackles. As a rule these ships were equipped by a fore- and a main mast but with the length of the ship more than 27.5 m one more mast had been installed - a mizzen mast. Two-masted shkoats carried a brig-rigging sails. Three-masted shkoats carried a corvette-rigging sails.