As you can imagine, the Eiffel Tower needs a lot of energy to operate. It is necessary for lighting, but especially to operate the 5 lifts and the elevator, which turn almost continuously from 9am to 1am. The machines were put in place at the construction of the tower, a few months after its inauguration and just a few days after the opening of the tower. the tower to the public, the inaugural day of the world exhibition, at least for the first machines. These complex devices were of a great power, but above all they had a rare capacity these days: They were planned to work a long time. So long that they are still in production today ... And yes, the machines running the lifts are still the same for almost 130 years! So of course, the energy is not the same, the machines are controlled by microprocessors, etc., but the mechanical parts are the same as at the time.
These machines have all been set up in the same place, in the basement of pile N ° 3, the one in the South. It had been planned for that since the construction, it was a machine room. At the time of construction it did not only contain traction motors for elevator cables, but also water tanks, hydraulic power machines, pumps, boilers, steam machines and machines. dynamos. The technical plans of the Eiffel Tower detailed their locations and their descriptions, everything is indicated on the boards XX and boards XXI.
The mechanical principle is simple enough to understand. A hydraulic machine propels a piston back and forth, taking with it a trolley on a rail which itself drives a set of pulleys pulling the cabin of the elevator. Now let's take a look at the details of the Eiffel Tower's machinery installations at the time of its construction, and the modifications that have been made to it today.
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Description of the machinery of the Eiffel Tower in 1889
Quantity of water to be supplied to elevators for the 1st and 2nd floor
The Roux, Combaluzier and Lepape elevators, as well as the Otis elevators, were served by two cylindrical tanks, 3 m in diameter and 7 m in length, installed on the 2nd floor of the Tower and with a capacity of 46.330 m 3, for both, 92.678 m3. These tanks were interconnected by a sheet pipe of 0.50 m in diameter, from which the four pipes leading to each of the cylinders of these lifts started.
The Roux, Combaluzier and Lepape elevators spent 8,746 m 3 of pressurized water by ascent; as each could perform 10 trips per hour, the pumps had to provide for these lifts 2 x 8.746 = 17.492 m3 in 6 minutes, or 2.915 m3 per hour. minute. An Otis elevator was flying 7.92 m3, and since both of them could perform 9 climbs per hour (without stopping on the 1th floor), pumps provide, for these lifts, 2 x 7.92 = 15.84 m3 in 6 minutes 40 seconds, or 15.84 x 60/400 = 2.38 m3 to the minute.
The pumps called Quillacq pumps, which feed the two tanks on the 2nd floor, must therefore supply a minute 2,91 + 2,38 = 5,29 m3.
These machines and pumps were studied by M. Meunier, a civil engineer, and built by the Société Anzin, represented by Mr. A. de Quillacq. They are two in number and composed as follows:
The steam engines are of the Weelhoek type, with Girard pumps in extension of the piston rod; they are double-acting and piston plungers. Each pump raised a volume of 50 liters at a speed of 22 turns and a half per minute and 80 liters at a speed of 36 turns. The height of elevation is 120m. The machines are condensing by mixing. According to the market, the introduction of steam is normally during 1/7 of the race under an initial pressure of 6.3 kg, or 7 kg to the generators. Under these conditions, the consumption must not exceed 11.6 kg of dry steam per horse-hour, measured in mounted water. The bayonet frame carries the cylinder of 650 mm in diameter, and 1,066 m of stroke with piston, rod, steam jacket, distribution and relaxation members, wooden casing on the outside of the cylinder.
The centrifugal force regulator acts directly on the trigger, and the steering wheel ensures a sufficient regularity of running at the maximum speed of 22 turns and a half. The air pump is controlled by a crank disposed at the end of the shaft, the side of the steering wheel; the diameter of the air pump is 350 mm and the stroke of 400 mm; it is equipped with rubber valves and a vacuum indicator. The hot water cover is closed; it is surmounted by a pipe allowing to raise the water to 1.50 m above the axis of the air pump. The food pump, 90 mm in diameter and 250 mm stroke, is a part of the air pump.
The machine operates directly, through the extended rod of its steam piston, a horizontal pump with double effect and plunger, Girard system. The diameter of the diver is 290 mm and its stroke of 1,066 m. The pump thus delivers per turn: 2 x 1.066 x 0.29 m2 / 4 = 0.140, ie 140 liters. However, we have seen that elevators required 5.29 m3 per minute. A single pump would be sufficient, if necessary, by walking at 36 turns, since it would give 140 x 36 - 5,040 liters. When they both walk at 22 and a half turns, they give 2 x 140 x 22.5 = 6,300 liters. The service is thus largely assured, since with a single pump it is possible to meet the maximum needs.
This pump consists of its cast iron piston with its steel rod, two cast iron pump bodies with large pads assembled firmly together. The four valve boxes are cast iron; the valves are lined with brass and leather and have steel springs. Both suction hoses are vertical; the discharge pants are cast iron, and the air tank, 1 m3 capacity, is made of sheet steel and mounted directly on the pump; it is equipped with a 250 mm diameter water outlet pipe, a metal pressure gauge, a water level tube with its valves, two filling and priming valves for the pump casings. and two air purge valves.
The test reports showed that the pumps could run regularly from 25.3 revolutions to 36.36 revolutions per minute, with an elevation of 124 m; that their yield varied from 0.92 to 0.95, and that the expenditure of dry steam per horse-hour measured in mounted water was 11 kg, which was lower than that of the market, which stipulated 11.60 kg as the maximum limit. The exhaust water from the cylinders of the 4 elevators goes through underground pipes to a tank where the pumps draw it to pump it back into the tanks of the 2nd floor. This reservoir, established in the eastern corner of the cell basement 3, has a depth of 2 m; it is covered by an iron floor consisting of a striated sheet placed on its joists.
Each of these machines has a force of 111 horsepower at an average speed of 31.6 revolutions, giving a real flow per second of 67.56 liters or per minute of 4.054 liters of water, mounted at the height of 124 m. These two machines were paid 60,000 francs, or 30,000 francs each, made on labor; in this price is not included the piping, nor the assembly costs, carried out the teams of assemblers under the supervision of a chief editor of the house Quillacq.
The Edoux elevator, which took visitors from the 2nd to the 3rd floor until 1983, was serviced by a 3m diameter and 4m high reservoir installed on the third platform. is 28 m. This tank is fed by two Worthington pumps, each comprising two double-acting cylinders, which take the water from the discharge tank installed on the intermediate platform, so that, in short, they have only to repress it a height of 80 m. These pumps were operated directly by compound machines with tandem cylinders. Their diameter is 0.195 m and their stroke is 0.340 m. The volume of a cylinder capacity is 10,166 liters for a piston surface equal to 299 cm2; when both pumps are running simultaneously, the number of displacements per revolution is 8, and the volume is about 81 liters. In normal good running, the number of laps is 30 per minute. The cube of water per minute is 2,430 liters, in actual quantity, and for a yield of 90%. 100, about 2,200 liters per minute. However, the Edoux lift, whose plunger has a 0.32 m diameter and 80.20 m stroke, per trip travels 0.0804 x 2 x 80.20 = 12.896 liters; pumps running for 6 minutes therefore provide the amount of water needed for a trip. They make it possible to make 10 journeys per hour, as we have ensured by direct experiences. This performance is above practical needs; as a result of the circumstances indicated above, only seven can be made. It is even possible, by operating a single pump, exceptionally at 35 revolutions, to operate the elevator for this number of journeys. The service of these pumps, which have always worked perfectly without any stop, thus largely ensures that of the elevator.
We have noted, for the speed of 30 turns, the pressure, on the discharge pipe and on that of the suction, to deduce the pressure losses due to the movement of water in these pipes. The manometer placed near the pumps on the discharge pipe bore a pressure of 285 m of water. However, the rating of this manometer was 30.50 + 2.00 = 32.50. The average water level in the upper reservoir is 307.50 m. It exceeds that of the manometer 307,50 - 32,50 = 275 m. The head loss in the discharge pipe is 285 - 275 = 10.00 m. The manometer of the suction pipe, situated at the same elevation as that of the discharge, gave a pressure in meters of water of 190 m. However, the water level in the intermediate reservoir is 229.83 m. The difference with that of the pressure gauge is therefore 229.83 - 32.50 = 197.33 m. And the pressure drop for the suction is consequently 197.33 - 190 = 7.33 m. These two pressure drops, of 10 m for the discharge and 7.33 for the suction, increase all the fatigue of the pumps, but they remain within very acceptable limits.
These pumps were at the time around 30 000 francs, but the exact price is unknown because it was included in the global package for installation of the elevator Edoux.
The engine room still contains the dynamos and their engines which are described on the page devoted electric lighting, as well as the pump Worthington, with a strength of two horses, drawing, in a special tank connected to a meter of the city, the spring water essential to the restaurants and the bars of the 1st floor and raising it in the tanks of this floor.
The steam required for these different machines was supplied by a battery of 4 multi-tubular boilers with rapid evaporation, of the Collet-Niclausse system. These boilers each had a heating area of 80 m2 and a grid area of 3 m2 They were stamped at 12 kg and developed per hour, in normal operation, 1,500 kg of dry steam at maximum pressure, ie 6,000 kg for all four. The charcoal consumption guaranteed on the grid is 1 kg for 8.5 kg of dry steam produced at a pressure of 12 kg. Three of these boilers, which represent 150 horsepower each, are sufficient in normal operation, the fourth being a reserve.
Each generator consists of 98 spraying tubes 100 mm in diameter and 2,250 m long, and 10 drying tubes 128 mm in diameter and 1.50 m in length. Inside each spray tube was placed a 60 mm diameter steerer tube, and a 20 mm iron tie rod holding cleaning plugs at both ends of the tubes. The tubular bundle opened at the front in 7 vertical collectors, equipped with their dividing partitions. These collectors were fixed, by means of conical seals, on the upper reservoir 900 mm in diameter and 2 m in length, which is provided with a water level, a check valve, a safety valve, a pressure gauge and gauge valves.
The generators were set up in groups of two with their masonry envelopes and the flues at the rear, up to the nude of the current wall which limits the chamber intended for the machinery; a sheet metal door closes the space between the two groups of generators, on the front of the two doors of the rear flue. These boilers were powered by food pumps (Worthington system), one replacing the other.
Their total price was 52,000 francs, fully installed, including the concrete block that supports them.
Smoke pipe and chimney
These boilers, contiguous two by two on the face of the Seine, combine their fumes in a 116.23 m long vaulted collector flue placed in the ground (board III, figure 2), having 1.30 m of width and 1.70 m of height to the key. These dimensions correspond to a section of 2.02 m2, equal to about a quarter of the grid area of three of the boilers running simultaneously. This pipe is equipped with two eyes for the visit and maintenance. One is placed near the boilers, and the other near the middle of the course. The flue comes to open in a brick chimney, hidden to the right of the pile 4 (West) (board IV, Fig. 15 to 22).
Primarily, this chimney measured 17.23 m above its foundations, which corresponded to a draft height between the boilers and the chimney outlet of 15.54 m. As this height was a bit low, despite the large exit diameter of 1.69 m, a gas-powered fan had been installed and forced air into the pipe to activate the draft. This fan was removed in the 1900s, and the chimney was raised by 1.50 m at the same time, giving a draft height of 17.04 m. This height is sufficient, and the chimney has a good draft. It should be noted, moreover, that its outlet section, ie 2.01 m2 also corresponds, approximately, to 1/4 of the area of the three grids, which is 9 m2. The current chimney rests on a massive 0.80 m thick concrete. It is built in three sections of different thickness, and whose height, starting from the base, is 5.00 m, 6.13 m and 7.60 m. The thickness of the chimney at the outlet is 0.35 m, at the base it is 0.70 m.
The price of the chimney is 3,500 francs, and that of the chimney of 13,500 francs.
The coal bunker (board XXI) is placed in the west corner of the basement; it is filled by a door placed on the Grenelle side; a Decauville lane then makes it possible to bring the fuel into the heating chamber.
The steam from the machines was sent into mixing condensers supplied with Ourcq water or Seine water taken from the meter; the repression took place in a tank placed near the boilers; some of this water, whose temperature is about 42 °, was used to feed the boilers with two small Worthington horses. The surplus was discharged to the sewer. The steam pipe that supplied the various machines was continuous and went around the basement; on it were connected the different steam catches (board XXI).
Modifications made to the machinery since 1889
Of course the current machinery of the Eiffel Tower has been modified, even if it remains in service, it was necessary on the one hand to modernize the mechanics, which accuses its age, and on the other hand to ensure the proper functioning. It was therefore necessary to make modifications to these machines, which, let us recall, were in the base of the pile No. 3, the south side.
The first modifications took place in 1900, with the improvement of the flue gas chimney, which had been undersized. To alleviate the problem, the engineers had added a small gas-fired engine that evacuated the fumes, but it was stopped and replaced with a chimney of an adequate size.
The system then operated throughout the twentieth century, exactly until 1986, when the pressurized water system was abandoned for a conventional hydraulic oil pump. of the three tanks, only one still served, the others being no more than a counterweight.
The most recent change is probably the most important. Started in 2008 and completed in 2012, the Western Elevator's machinery has been completely redone, more than a renovation, it's a real restoration that has been made. It is followed by the elevator East. The work concerned the cabins, but especially on the machinery, with the replacement of the trolley which carries the cabin, the rail of the trolley, hydraulic system and engine control system. These controls are completely computerized nowadays, they are microprocessors that manage the elevations of the cabins, but on the other hand, we are always on a hydraulic system, that is to say that it is always water that is transformed into steam , which propels a piston back and forth, driving a cart that pulls the lifting cables. One would have thought that the system had been replaced by electric motors, but it is not so.