ARTICLE

Historical reference

        This is the most numerous class of fast steam locomotives in the whole history of the Bulgarian State Railways. The first three units gave birth to the new constructive design, which was later on adopted in our railways. This class was formed and finally finished in 1935 by five different locomotive factories – three German, one Polish and one Swiss. Nevertheless, the different deliveries did not have essential differences in their mechanisms, because they were built using the same constructive documentation. Some of the factories did make aberrations (feed-devices, tender driving part, coal bunker, water lids, sanding installation etc.), but we must say these were actually intended as a modernization and improvement of the construction design without risking the standardization capabilities of the different parts and mechanisms, not only in class 01, but also in the locomotives of series 10.00 and 46.01 – 46.12 that were delivered in the same time.
        The above mentioned standardization was one of the main achievements of the new constructive design, widely spread within our railway literature.
        An interesting thing to know is the fact that the last six units of the 01.00 series were the only Swiss locomotives ever delivered in Bulgaria . As an achievement of the company we can say they were the biggest steam engines built in SLM – Winterthur .
        Particularly these six engines were delivered with a delay of two months or so. By a written statement from the 20 th of December, 1935 , the reclamation committee of the administration reviewed the request for delivery of the locomotives to be prolonged. The committee found out the reason for the delay was caused by the Control Authorities of BDZ, therefore postponed the delay with 93 days. This settles the question of possible financial penalties that should be assigned to the factory because of the delay.
         Through its representatives in Sofia – Dorken & Kolmann, the SLM – Winterthur demanded a certificate confirming that the Administration of the Bulgarian National Railways was satisfied with the delivered in 1935 steam locomotives. ”This certificate will serve to the company as a reference” – said the letter from 26 th of February, 1936. Such reference was issued on the 11 th of March, 1936 . It said: ”The Administration of the Railways and Marine Ports – Traction Department, issues the following certificate to the Swiss locomotive factory WINTERTHUR in order to testify that so far it is satisfied with the delivered in 1935 six locomotives of type 1 – D – 1.”
        The definitive admission of the locomotives took place in the Sofia Depot on the 29 th of December, 1936 . Without reproaching the very good relations between Traction Department and SLM – Winterthur, as a background on the above mentioned certificate, we can specify that to the written statements for concluding acceptance, were attached bills for the work carried out on the locomotives from the temporary until the definitive admission, as for the more important staffs, like it follows:

• 01.18 – Blocked piston pipe, stuck connections, making of cylinder gaskets on several occasions etc.


• 01.19 – Leakage through a joint of the external right hatch, that lead to the dismantlement of the fourth right couple bearing, torn bolts on the returning springs of the bogie, cracked bell of the steam whistle, stuck connections and so on.
  
  
• 01.20 – Torn connections of the firebox etc.


• 01.21 - Torn clamp of the left returning spring, fallen right returning string, stuck connections, abdominal connections and so forth.


• 01.22 - Torn bolts of the bogie returning springs, torn and stuck connections, torn abdominal connections of the firebox etcetera.
  
  
• 01.23 - Repairs of the left returning spring, torn abdominal connections and others.
  

                Afterward, on the 16 th of April 1937, the disk of the left valve-piston became loose in the pipe of locomotive 01.22.

        On the 2 nd of March 1940 , all the locomotives were inspected on the expiry of their paint and bandage warrantee. The committee decided that a sum between 8400 and 11300 per locomotive is needed for the conduction of the repairs of the paintjobs and the bandages. After these repairs the warranty of the paintjobs and the bandages was taken down.
        The above mentioned details, concerning the warranty terms of the locomotives 01.18 – 01.23 were taken right from “the spot of the action” (which is unknown for many) during the delivery and admission of the new traction units and might serve as an example for the usual work in this respect during the steam traction in the Bulgarian Railways.
        In 1938, yet another phenomenon was noticed in the locomotives of our first modern steam class - the connection between the steam cylinders and locomotive frame became loosen and cracks appeared in the zone between the frame and the steam machine. Due to that, in 1939 at the main railway workshop, nine of the locomotives had their steam cylinders dismounted, frames straightened; the apertures reamed and new pass-bolts made for the flange connections of the frame.
        In the same 1939 , locomotive 01.0.5 broke her right frame joist on the front angle of the axle - box cut-out of the first driving axle.
        In the beginning of November 1939 , was announced an auction for the delivery of right frame joint according to drawing № 8.04 , however competitors did not appear. To the questions adressed to BORSIG, HENSCHEL and KRUPP, answered only the last company; suggesting to deliver two joints (left and right, in respect to drawings №№ 8.03 and 8.04 ), for the milling of a single axle was technicaly impossible.
        The conversations began on December the 27 th and successfully finished on December the 30 th 1940 , when an agreement was concluded for the delivery of two frame plates, all together coming to 419 100 BGN, as the term of delivery was 8 months. Actually the frame plates arrived in Bulgaria on 16 October 1941; received by a committee in the main railway works on 18 November, as later on was started the repair of 01.05 locomotive. The Fr.KRUPP-Essen company initiated itself several researches in the drawings documentation of our steam locomotives and by its representative in Sofia - Dochev, Kosta P, on 17 November 1941 under a signature Lowa-A-№ 378 , it made an official proposition for the remaking of our 01 class into one of the follwing three variants of the “Drilling” system: 1D1-h3, 2D1-hЗ or 1 D2 -hЗ .
        After the establishment of business relationships and the preliminary negotiations, the KRUPP Company sent an offer on 18 February 1942 , which was concerning the reconstruction of 5 locomotives of the 01 series type B 1-4-1 17 a nd a “ Zwilling” machine, into type B 1-4-2 17 and a "Drilling” machine.
        In order to avoid the high transportation costs, the company suggested to conduct the reconstruction in the main railway workshop in Sofia , under the guidance of their specialist, instead of into the KRUPP's factories. Drawing № 17232 that was supposed to be used during the reconstruction, was also attatched to the offer. The parts marked with red color were those who had to be dellivered by KRUPP and those marked with blue were to be modernised in the main railway workshop – Sofia .

        In the offer were enumerated the parts that were to be delivered and the most important of them were:

• Three new steam cylinders, along with the slide valves and a kit.
• The second and third driving axles and a kit.
• The internal crank moving assembly and a kit.
• A double-axle bogie with sliding bearings in jacks of Frideman, a kit etc.

        In the preliminary conversations the head administration of BDZ wanted to replace the front driving axle of O 850 тт with a O 1000 тт one, but the company responded that this would weaken the front part of the locomotive frame, and after that the head administration renounced its suggestion.
        Examining the offer was assigned to three of our best locomotive specialists in these times: engineer Gotsev, Stoyan – chief of the main railway workshop – Sofia, engineer Petrov, Petar – head of traction mantainment department in the main administration and engineer Milev, Nikola – head of Sofia and traction depot. This comission composed a written statement, dated 27 April 1942 , which aprooved the suggested offer. The head administration of BDZ was ready to conclude the contract. The sum of 17 millions BGN demanded for the modernisation of the first five locomotives was supplied. However, on 23 June 1942 , a letter arrived from the KRUPP Company, saying that the company was unable to deliver the necessary parts (probbably due to the enormous amounts of orders for the war) and therefore asking for a postposal of of the order in time. This is how finished, and subsequently due to explicable reasons ( the exit of the war and the post military situation ) never conducted the modernisation of class 01.00 locomotives.
        Later on, following another discussion in Bulgaria, a new, simpler decison was taken – each time a locomotive arrives in the main workshop for an overhaul, to drive in cast-iron cyllinder mantles or to mould new cyllinder blocks, so that after the final processing, the initial drawing diameter of 640 mmto be shorten to 595 mm. thus lowering the cyllindrical forces tension in the consolidation zone between the steam machine and the frame of the locomotive.
        As we have already mentioned in another place, the locomotives of 01 class were in a terribly poor condition at the end of the Second World War and most of them gradually fell into disuse while waiting for overhaul. This is why the decision of diminuition of the cyllinder diameters was being realised in 6-8 years. This was also helped by the fact that after the first few overhauls, the replacement of the cyllinder blocks was prefered than driving in of cast-iron cyllinder mantles. Subsequently, when by one or another reason the new cyllinder blocks had to be moulded, they were manufactured in their initial size of 595 mm. And to conclude the matter of the cracks in the frame and the consolidation of the steam cyllinders, we could say that after the diminuition of the cyllinder diameter and while the trains being served by those locomotives were comparatively light, the break-downs of the descripted character quieted down.
        However, very soon all of the fast and normal trains on the main lines reached gross weights that were equal to or above the utmost potentialities of the steam locomotives. As a result, later on 1956-1957, in a number of cases the cyllinder blocks were weakened from the locomotive frame, mainly the left ones. The reason for this phenomenon was the strong greasening of the contact surface and the bolt connection between the block and the frame by the Knorr pump, which was factory installed on the left side of the steam chamber. Initially, grease-collecting tins were installed under the Knorr pump, in order to collect the pump wasting oil and condense, leading them away of the node.
        At the same time, in the Railway Factory “G. Dimitrov” was developed a constructive documentation for the shifting of the Knorr pumps. They were mounted on a special bracket, on the right side of the locomotive, under the side platform between the third and fourth driving axle. The bracket which was fixed on the locomotive frame is a welded construction of steal plates (similar to the one of 11.00 class). The shifting of the Knorr pumps itself was carried out from 1959 to 1962, while the locomotives were entering for current repairs or overhauls.
        With the increase of the gross weight of the trains, another old familiar phenomenon reminded for itself – the cracks in the frame plates (beams) in the zone of the axle-box cutting. Experts said that in terms of the whole contingent of locomotives of this class, later on 1956 and during their intensive use, this phenomenon was observed on the average 1-2 times per year. Of course it was no longer thought about delivering new frame beams. In the Sofia Depot was acquired a technology for their welding, as speaking in short, this is what the sequence of welding was: dismounting of the first driving axle and return of the joints under the driving-axle on their place, positioning the locomotive on a leveled track with an extra support of the frame, release of the frame connections immediately near to the place of the crack, exterior V-riveting with a pneumatic gun on an approximately 90° angle in a 700% depth of the beams’ thickness (90 mm). Riveting from the interior part, welding with high quality electrods, while deep cleaning the slag and pauses after every welding layer until the complete recovery the the beams’ section of the interior and exterior sides, abrasive shaping of the surfaces after the completion of the welding, annealing the place of the welding with wooden coal in a special container, embracing all of the parts of the welded place, and finally painting, mounting of the first driving axle and all of the other dismounted or weakened parts. In terms of time, all of the operation in depot conditions was taking 2 or 3 days, as only the welding required about 10 and 15 hours.
        The biggest part of the exploitation life of the locomotives class 01.00, passed in the Sofia Depot. Until 1965 this is their only home and during all that time they were the main fast series of the Sofia Depot. They served trains on the traction branches: Sofia – Plovdiv , Sofia – Pleven (several years to G. Oryahovitsa), Sofia – Karlovo (several years a pair of season fast trains to Burgas), Sofia – Dimitrovgrad JZ (in the past – Tsaribrod), and at the end of the period Sofia – St. Dimitrov (today Dupnitsa) as well as separate trains Sofia – Vidin .

Accidents

        During its continous exploitation in Sofia Depot, the most serious accident with a locomotive of the 01.00 class; is considered to be the fall of 01.22 along with the bridge near the Sveta Petka station (Yugoslavia).

        Since the beginning of autumn 1944, the Sofia Depot started to attend the war echelons with Bulgarian and Russian troops from Sofia to Nis. Due to a series of temporarily restored bridges on wooden pilots in the Serbian part of the line, at that time locomotives with a lighter axle load and smaller total weight (usually DR class 52) were used there. However in November one of the echelons continued its journey from Tsaribrod (today Dimitrovgrad – JZ) further with a 01.22 locomotive – the first engine of this class ever passed enroute the area. The personnel knew that. Before the bridge, near Sveta Petka station, the echelon was stopped by the maintenance authorities who disagreed to let the train pass, because of the heavy weight of the locomotive. The soviet war commandant ordered to make a “test-pass” with the locomotive only, and then go back and couple the rest of the train and continue. 01.22 passed with low speed (“crawled”) successfully, but those who have heard the tale of the witnesses relay that “… the bridge was craking menacingly”. However, on its way back the apparently weak bridge could not withstand and broke in two, falling down into the river along with the locomotive. In the bashed cab died pressed between the engine and the tender: the engineer-driver Nikola Georgiev Dimitrov, the fireman (co-engineer) Asen Ivanov Tonev – both from Sofia Depot, as well as an Yugoslavian locomotive instructor, who was with them.

           Later on this unfortunate accident the bridge was rebuilt, this time for a higher axle load, as all the others were reinforced additionally. Thereby the obstacles for safe traveling of the locomotives from classes 01.00 and 10.00 were eliminated; however it was avoided to let them pass beyond Tsatigrad.
            The 01.22 locomotive was brought out of the river in March 1945 and turned back to Sofia in two parts: the machine apart of the tender. Until the end of 1945, the engine was reconstructed in the Main railway workshop.
            For those who like details, we can say that in the beginning of 1945 was marked the lowest participation of class 01 locomotives in the transportation activity during their whole exploitation life. At that time only two units of the class were operational – 01.02 and 01.12, and the rest were parked, waiting to be overhauled. In the same year, with supreme efforts Sofia Depot managed to put in motion another two engines – 01.01 and 01.03 - mainly for lighter trains, because of their bad condition. Until 1949 all the engines of the class passed through factory overhaul, except 01.08 which had been “hanging about” ever since 1941 with broken frame of which were dismounted many parts and nodes for other locomotives to be restored. The engine remained put away in the southwest part of Sofia Depot, among other old and damaged locomotives.
        Due to a decision some of the machines involved in accidents and ineffective for exploitation to be obliterated from the inventory lists, it was considered that the restoration of locomotive 01.08 would become too expensive (about 24 million BGN according to the course of exchange at that time). Because of that, by order № 295, dated 21 March 1952, she was discarded. It was prescribed the steam cauldron to be dismounted and preserved as a spare one for the locomotive classes 01.00, 02.00, 10.00 and 46.01 – twelve in LVZ “G. Dimitrov” – Sofia, as the tender to be transferred at Sofia Depot, where it could be used as a substitute part. After the dismount of the locomotive, the frame was put onto wooden sleepers and was left in the yard of Sofia Depot.
        In 1958, when the lack of locomotives was felt especially sharp, and the delivery of the 30 diesel locomotives from MaK (Germany) failed, the restoration of series of severely damaged locomotives was undertaken, including the restoration of 01.08 as an engine of full value. The frame was sent to LVZ “G. Dimitrov” and was thoroughly welded and set to be supplied. The tender, which  after some “exchanges” had number 01.15 on it and the spare steam cauldron – too. After the completion of the locomotives’ wheel pair axles and other siginificant parts, the restoration of the locomotive began.
        By the end of 1959 locomotive 01.08 was ready to conduct trial trips. After their completion, she was once again put on the list of Sofia Depot and included into the timetable of the fast locomotives on an equal footing. Thereby the class recouped its initial number of 23 units.
        In 1957 tests with locomotive 01.23 were conducted by the Scientific Investigation Institute of Transport and the results obtained were used to constitute the traction, thermotechnics and delivery characteristics for class 01.00. In 1958 they were published in a special brochure.
        During the whole exploitation period, into and from the 01.00 class locomotives were dismantled, isolated, replaced or newly installed a variety of systems. Some of the more significant mechanisms and parts were as follows: water-heating system “Knorr” with a water pump, replaced with a supercharging injector “Korting” (only in locomotives 01.01 and 01.03); an isolated extra brake with anti-pressure system “Riggenbach”; dismantled automatic valve “Marcotty” for the siphon, since 1954 was installed an air servo-system for the opening and closing of the furnace door (“Michnev” apparatus); since 1957 on all the locomotives of this class were installed four circulation tubes in the furnace (after the introduction of the black oil as a fuel they were removed); until 1962 were dismantled the air equalisers and were installed new slider rule equalizers from the “Trofimov” type; by 1962 all the locomotives of this class were equipped with and installation of compound oil-carbon combustion (by 1966 some of them were reduced to full black oil combustion); by 1966 on the majority of the locomotives of the class were closed the drivers boxes between the engine and the tender (in not so successful manner – mark of the author) in order to improve the work conditions whilst traveling in reverse.

The faith of the class

        Later on more than 30 year service in Sofia Depot, class 01 was removed from the capitals’ rolling stock. Since 1965 began their gradual transfer to the Plovdiv, Stara Zagora and Varna Depots, while the location of the last machines was changed in 1968. The sent locomotives worked in the mentioned depots from 6 to 10 years, later on they were held as reserve. The first engine of the class to leave the railways was 01.18 – which was transferred from Varna Depot to the shipbuilding factory “G. Dimitrov” – Varna in 1975 where she was used as a heater till 1987, when she was destroyed. In 1976 locomotive 01.21 was cut up for scrap by mistake, which because of someone’s irresponsibility or for no apparent reason, fell among the discarded locomotives (sold for scrap), on the track behind Smirnenski (Slatina) station in Sofia.
        With a statement № 63 from the 21st of Novemberm 1989 was discarded locomotive 01.20, which was standing for a long time near other abandoned and discarded engines on Station Sindel.
        All the other locomotives were not discarded until 1990. They figured as locomotives held as reserver or purposeful preservation and by the end of the same year they were situated as follows:

• №№ 01.01, 01.04 и 01.11 in locomotive Depot Karlovo;
• №№ 01.02, 01.03 и 01.17 in the Bodrovo base;
  Until the end of the heating season locomotive N 01.03 was used as a heater in Poduyane Depot;

• №№ 01.05, 01.06, 01.07, 01.08. 01.09. 01.10, 01.12. 01.14, 01.15 and 01.22 on the Asenovo Station;
• №№ 01.13 and 01.16 in Station Kaloyanovec;
  In 1988 locomotive № 01.13 pulled a jubilee train in the Plovdiv railway district;
  
  
• № 01.19 in Station Strunen;
• № 01.23 in locomotive Depot Sofia. Since 1988 she was reconstructed and ever since it has been kept as a museum locomotive of BDZ. On the 24th of December 1988 this engine pulled the jubilee train “100 years Railway Traction and Sofia Depot”. After that she took part in many attraction journeys as well as such for the needs of the cinematography.

        In 1990 were established relations with two foreign associations by their inquiries as follows:
        VAPEUR VAL-DE-TRAVERS from Switzerland, for the purchase of one locomotive produced by SLM-Winterthur (01.19 was chosen) and HANOMAG INTERESSENGEMEINSCHAFT FUR HISTORISCHE FAHRZEUGE E.V.from Germany for the purchase of one of the locomotives built by HANOMAG-HANNOVER from the 01.00 class and one from class 45.00, built by the same factory.
        By the end of 1990 prices and technical details concerning the restoration of the locomotive were defined more accurately (by correspondence), with the first association, while official and personal contacts concerning the same matters were established in Sofia with the second one, but, eventually, without no contracts were signed.