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Nazi Germany attacks the Soviet Union and the power plant is blown up
During the war in 1941-1944, the Tallinn Power Plant had to survive difficult times. Plans to further expand the plant were interrupted due to the attack by Nazi Germany on the Soviet Union on 22 June, 1941. The withdrawing Red Army and destroyer battalion were instructed to evacuate bigger equipment from the power plant. On 27 August the power plant was evacuated – of the major equipment turbo generators with a total output of 26.75 MV *A, 22 transformers, 18 tons of cables and other devices and materials were taken behind the front line. In the eve of falling into the hands of the Nazis, the leaving detachment of the demolitions team of the red power exploded the machine room of the power plant along with the turbo units remaining in the plant, the boiler house and old brick chimney. Tallinn was left without electricity.
During the German occupation construction work of the power plant is started again
During the German occupation administrative restructuring was taken up first. The trust Estonian SSR Electricity became the Electricity Centre Estonian Electricity subordinated to the economy and transport directorate of the Estonian Municipality. Until 16 June, 1942 the Tallinn Power Plant was subjected to the municipality, thereafter the plant went over to the Germans. The name of the institution “Eastern area energy supply association. Estonian commissar general area. Countrywide power stations and grids”. The plant itself was named the Tallinn Power Plant and grids. From there on, the power plant did not belong to the municipality.
During the German occupation electrical engineer E. Voot was named director of the power plant. He was a former manager of an electricity laboratory. However in practice the plant was led by a German army representative named Neumann. The employees of the power plant were issued temporary certificates of competence and they started restoring the Tallinn Power Plant. In the first place the Germans tried restoring Tallinn and power plants and transmission lines supplying the oil shale industry of military importance. Partially it was done at the expense of relocating the equipment of other plants. In such a way the 5 MW turbine was taken from Ulila to the Tallinn Power Plant given to which the output of the plant reached 17 MW. Getting electricity in wartime conditions was an enormous benefit, especially since men were constantly being recruited to the army and there was a shortage of people who could have helped in restoring the plant. In addition it was difficult to get fuel because the oil shale industry had been destroyed and consumers were asked to save electricity.
With any request the commandant of the City of Tallinn had to be addressed. In case the request was justified, the Tallinn economics team asked the applicant to go to the office of the Tallinn Power Plant, where after technical feasibility surveys had been carried out, the request was approved or not.
Russians invade the city, the Tallinn Power Plant is subjected to Estonian SSR Electricity – the People’s Commissariat trust of the Estonian SSR community amenity
In 1944 the retreating Germans fired at the plant from the sea with dozens of shells, as a result of which the building of the boiler house, as well as three newer boilers and the metal chimney were damaged. The roof of the boiler house caught fire but the workers managed to extinguish it. The equipment could not be taken to Germany, as the German disassembler failed to fulfil his task.
Once again one power had been replaced with another and the power plant was damaged but this time it was still able to transmit some power. They managed to start the 6 MW turbo generator and boilers no. 1 and 2. Yet the operation pressure and generated steam quantity was less than required by the turbine required and thus the unit was able to provide only 2.5 MW. However the operation of the plant was hampered by a shortage of fuel, as the power plants in the oil shale region were down and the mine needed electricity. The supply of oil shale was restored only by 26 November 1944 and even that in small volumes (50 to 100 tons per day).
On 27 June, 1945 a new 6 MW generator from Siemens-Schuckert was implemented. The Tallinn Power Plant was subordinated to the Estonian SSR Electricity – the People’s Commissariat trust of the Estonian SSR community amenity. On 20 June, 1945 the trust Estonian SSR Electricity was given over to Estonian Energy subordinated to the People’s Commissariat of USSR and the plant was renamed the Tallinn Energy Region.
Electricity-saving regime and planned economy
Due to the deficit of electrical energy, consumption limitations had to be imposed on businesses and institutions in a volume of around 60% from the consumption in December 1940. For lighting a room 5 kWh was permitted and in addition 10 kWh per month was allowed for a family for general needs. To prevent current consumption over the limit, current limiters were used. In September 1946, the Council of Ministers of the ESSR established new provisions for the use of electricity. In case an institution consumed electricity above the limit or even used electrical stoves to heat their rooms, it had to pay a fine of up to 10,000 roubles.
From now on work had to be planned to be able to fulfil the plan and to determine a percentage the plan was exceeded in case the job was completed before the deadline. Those who were constantly exceeding the plan were awarded the title of a foremost worker, which was very often accompanied by a financial prize. Electricity cannot be produced more than it is consumed but the consumers were facing a strict limit and they were required to save electricity. Thus preparing a plan for the power plant was an impossible mission from the very beginning.
The plan of recovering and developing the economy of the ESSR included expansion of the Tallinn Power Plant. The plan was prepared by an engineering organisation in Leningrad called Lenpromenergoprojekt. In this plan it was foreseen to expand the new boiler house, to build a new chimney and a transportation system of fuel based on belt conveyors and a hydraulic ash discharge system. In 1946 it was planned to build a new boiler house, which was to begin on 1 April, 1947. However the preparatory work took longer than planned. For example the attitude of construction trust no. 1 towards work was really foolish – rails meant for cars for carrying soil running from the foundation ditch to the sea crossed the railway in four places. When the train came, the rails of the cars were disassembled and after this assembled again and so many times a day. “Valuable work hours are lost there,” complained the Õhtuleht.
Spectacular construction work – the tallest chimney in the Baltic States and a spectacular trestle are built
On 27 March, 1948, the Tallinn Power Plant got the highest chimney in the Baltic States. Starting from the foundation the length of the chimney was 102.5 m. Reinforced concrete was made in a volume of 900 m3 and 57 tons of iron framework were installed. In total 800,000 chimney bricks, 100,000 standard bricks and 500 tons of cement were used. The equipment fleet of the power plant also got an addition, namely turbo unit no. 4 with an output of 6 MW arrived from Germany.
Technical innovations were implemented in relay protection, automation system, telemechanics and measuring instruments. The first automatic reclosing relays were implemented in 1949. In 1955 a new high-voltage distribution device, which also included equipment for voltages 6 and 35 kV, was completed. In the same year the power plant got a new contact board manufactured by Elektropult, a plant located in Leningrad.
It was not until 1951 that a hydraulic ash discharge system was introduced. A year later transportation of ash to the beach by using this method was stopped. The present City Hall is built exactly on this ash field.
In 1954 the trestle meant for transporting fuel and the first line of belt conveyors, the building of which had started some years before, was finally completed. The transportation capacity of the line was 120 tons of fuel per hour. Fuel was lifted on the belt by means of an excavator and was transported to the boilers on three consecutive belts. The second line was ready the next year and the cableway was demolished. Finally transportation of fuel was completely mechanised.
The power plant is turned into an enterprise producing heat
The efficiency of the power plant started falling behind and thus a plan was made to change the power plant to an enterprise producing heat. 60% of the fuel used in the Tallinn Power Plant was directed uselessly to the sea as heat of cooling water and as turbines no. 2 and 3 supported steam extraction, establishing a district-heating network for Tallinn was included in the five-year plan.
The initial plan was to heat over 50,000 apartments in the city. Thermofication was supposed to reduce heating costs and make air cleaner. A boiler was planned in the plant, main pipelines were designed through the plant via branch pipes to the heat assemblies installed in the houses, which had to be built according to this plan. The main piping consisted of two 500 mm steel pipes insulated with mineral wool and installed in the reinforced concrete ditch. The construction work was assigned to Estonian Energy Construction and Assembly Department and the design of the boiler unit was prepared by the Leningrad department of the engineering institute Promenergoprojekt. The piping ran from the power plant via Rannavärava Street and Mere Boulevard to Viru (Stalin) Square. However the working speed was very slow due to such obstacles as high ground water and closely placed underground power, water, communications and gas cables.
On 22 October, 1957 the facility was renamed the Tallinn Heat and Power Plant and by this time the last turbine was also adapted for steam extraction.
By 1959 the electricity production had reached 144.3 kW until a 100 MW turbo generator was implemented in the Baltic Power Plant, after which the main focus was directed to increase heat production. It can be seen from the report of Estonian Energy for 1960 that the first heat energy consumer was the administrative building of Estonian Energy, which was connected to the heat pipeline on 22 January 1960.
In order to increase heat production, a new water boiler was needed. The National Economy Council chose a boiler PTVM-100 (Russian alphabet!) with a capacity of 100 Gcal/h. The boiler was installed in a place of an old boiler, which broke down in 1963. The boiler had a steel chimney with a diameter of 3.5 m and length of 55 m and in addition two 2,000 m3 reinforced concrete containers were installed.
In December 1960 only 6% of the heat capacity of the plant was used as building distribution networks and house connections developed more slowly than building heat network main piping and from the money allocated for this only 17% was used. In 1961 the cableway and the depreciated 75 m long metal chimney were demounted. In 1963–1967 the plant had two chimneys.
Employees of the power plant participate in sports and amateur performance activities and also in political education workshops
The employees of the power plant participated successfully in sports and amateur performance activities. They participated in handball and light athletics competitions, a swimming section and basketball and volleyball teams were formed. There was a folk dance group, brass orchestra, male and female ensemble and a drama club performing a folk piece titled “A Suitor from Rakvere”, for example. Comrade Vaimre conducted a big mandolin orchestra with 24 members in total. The work of a cultural commission was hampered by the fact that they were not allocated any financial funds. Where these funds had disappeared, the cultural committee could not say.
In the early 1960s a new term was introduced – communist work movement. Great emphasis was placed on political educational work. To this end political educational workshops were formed. In these workshops comrade Stalin’s book The Great Patriotic War and the constitutions of the USSR and ESSR were discussed in a systematic manner.
Transition to liquid fuel, the plant is renamed the Heat and Power Plant Tallinn
The use of oil shale was stopped at the beginning of July, 1965. Thanks to the transition to liquid fuel, the smoke cloud constantly upsetting the residents disappeared from above the city and it marked the beginning of a new stage in the work of the plant. In this way personnel and fuel costs were reduced and the efficiency factor of the plant was increased. At the same time the heating surfaces of the boiler started corroding because of the high sulphur content in black oil.
In 1965 a 35 kV distribution device was reconstructed. It was provided with two 35/6 kV transformers with a capacity of 15 MVA each. 35 kV cable installed between the Endla substation and power plant allowed consumers in the city to be supplied with electricity from the Baltic Power Plant via the distribution device of the plant, if needed.
In 1966 the first turbine was rebuilt in order to increase the heat capacity. According to the design prepared by the Leningrad branch of the Orgenergostroi institute, the two last stages were removed from the rotor of the turbine and the capacitor was rebuilt.
In 1967 the power plant was renamed the Heat and Power Plant Tallinn and the entire enterprise with the added heat resources were renamed the Tallinn Heat and Power Plant. Due to the boiler implemented in the end of the year, the heat capacity of the plant reached 267 Gcal/h and there was nowhere to develop further – there was not enough free space.
The plant produces its last kilowatt-hours of electricity and it is renamed the Tallinn Heat Network
While repairing turbine no. 2 dangerous external cracks were found in the fastening points of the blades of diaphragms and thus in 1975 a decision was made to dismount turbo unit no. 2 and boilers no. 3 and 4. The remaining three turbo units remained in reserve and they were still used during the repairs of the energy system until 1979.
On 2 February, 1979 the plant produced its last kilowatt-hours of electrical energy and from that day on, the turbo units of the plant remained silent for ever. Production of electricity was stopped in 1979 at a time of launching the new Iru Power Plant meant to supply Tallinn with heat and electricity. The former Tallinn City Central Power Plant producing and distributing electricity had now become an enterprise producing and distributing heat and from 1 January, 1982 the name of the company was also changed due to the nature of the production. Now it was named the Tallinn Heat Network.
The entire energy management discussed above was subjected to Estonian SSR energy and electrification production unit Estonian Energy with its many divisions and institutions. In 1971 Estonian Energy was subjected to the Energy and Electrification Ministry of USSR and it was renamed the ESSR’s energy and electrification production main unit Estonian Energy.
Just as Tallinn will never be ready, the Tallinn electricity network will never be ready, either. The Old Man of Lake Ülemiste will still have a long wait until Tallinn is completely finished.