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01:00on the German railways, thank God, is very rare.
01:05And yet there is a possibility for this,
01:09if the locomotive driver fails once,
01:14if he as a human being becomes the victim of a deception,
01:20a mistake, or a sudden weakness.
01:27All of you, my dear listeners, know the main signal,
01:31which, by positioning its signal wing,
01:34gives the train free movement or stops.
01:37You probably also know that at a certain distance from the main signal
01:42there is a pre-signal that indicates to the locomotive driver
01:47which position of the main signal he has to expect.
01:51Stop, free movement without speed limit,
02:00or free movement with speed limit.
02:07In order to make the locomotive driver aware
02:11that he is approaching a pre-signal,
02:15on the main railways in front of the pre-signal
02:19there are still announcement beams set up.
02:22Usually three.
02:25100 meters in front of the pre-signal, the first beam
02:30with one cross-strip going to the right.
02:35175 meters in front of the pre-signal, the second beam
02:39with two cross-strips.
02:43350 meters in front of the pre-signal, the third beam
02:47with three cross-strips.
02:49The distance between the pre-signal and the main signal
02:53has become larger and larger over the years.
02:56It now measures 1,000 to 1,200 meters on individual routes
03:01so that the locomotive driver has a sufficient braking distance
03:05to the main signal even on the fastest trains.
03:09The probability that a locomotive driver
03:12does not pay attention to all these signs is extremely low.
03:16Nevertheless, the German Reichsbahn has not left anything untried
03:22in order to close this small gap in the train security.
03:29This is done by train influence.
03:34That is, by the direct impact on the train
03:39when the locomotive driver is turned off,
03:42when he threatens to exceed a stop-signal
03:47or on a section of tracks that can be driven slowly,
03:53the speed of the train is not measured according to the regulations.
03:58For this purpose, the German Reichsbahn
04:01applies three different procedures.
04:05The mechanical barrier on the Berlin and Hamburg
04:09city, ring and suburban lines,
04:12as well as the inductive and optical train security procedure
04:17on long-distance trains.
04:20All these procedures are designed as additional security measures.
04:27The responsibility of the locomotive driver
04:30and his driving skills are not excluded,
04:33but only intervene when he should really fail.
04:40I would now like to explain their effectiveness.
04:45If you consider that of the 1.5 billion travelers
04:51who travel with the German Reichsbahn every year,
04:54around 500 million, that is, a third,
04:58fall on the Berlin and Hamburg suburban lines,
05:03then you recognize the importance of the mechanical barrier
05:07that protects the train traffic on these lines.
05:12An essential component of the mechanical barrier
05:16is a barrier rail arranged on the track
05:21that, when the signal is stopped,
05:24slides into the space between the car profile and the light space profile,
05:29and when the signal is driven,
05:32it is folded up.
05:35The barrier rail is always coupled to the main signal,
05:40either mechanically or electrically,
05:43regardless of whether it is wing signals
05:51or daytime signals,
05:56whether the signals are near the track
06:00or are arranged on signal bridges.
06:06There is a trigger lever on the engine of the S-Bahn trains.
06:12If a train overruns a stop signal,
06:16this trigger lever is converted by the barrier rail,
06:21the air pressure brake is activated,
06:24the drive current is switched off,
06:27and the train is thus stopped.
06:31If, on the other hand, the barrier rail is folded up,
06:36the signal is stopped,
06:39the trigger lever of the engine car cannot touch the barrier rail.
06:44The mechanical barrier rail has proven itself well on the city railways,
06:49where greater train speeds than 80 km per hour do not occur.
06:56However, on long-distance railways,
06:59which today are driven at speeds up to 160 km per hour,
07:05the requirements for other means of train influence had to be met.
07:13Here, in the first place, the inductive train security is to be mentioned,
07:19whose development the Reichsbahn has drawn its special attention to,
07:24and which it now, after years of careful testing,
07:29incorporates into its routes.
07:33It is based on the following basis.
07:37An iron core,
07:40wrapped in wire,
07:42which is called a heart by alternating current with a certain number of vibrations,
07:47is passed through,
07:49transmits invisible energy rays,
07:53so-called electromagnetic power lines of the same number of vibrations.
07:59A magnetic field is formed.
08:03An iron core of this kind is attached to engines and locomotives
08:09at a certain height from the side.
08:12Through the wiring built into the interior of the protective housing,
08:16alternating current flows,
08:18which is generated by a generator on the locomotive.
08:24The locomotive magnet is connected to an apparatus box
08:30on the driver's cab of the locomotive.
08:33Here, a magnetic switch is installed.
08:38Through the alternating current,
08:40which also flows through the locomotive magnets,
08:44the anchor of this magnetic switch is fastened.
08:48On the track,
08:50attached to the rails on the side,
08:53are the so-called track magnets.
08:57They also have an iron core and wiring inside
09:02and are switched in such a way
09:04that the track magnet is tuned to the number of vibrations of the vehicle magnet.
09:10The track magnet does not have its own current source.
09:15The track magnets are connected to the signals in such a way
09:20that when the signals are changed from stop to drive
09:26or from warning to driving
09:30by contacts that are controlled by the wing or the disc,
09:35the track magnet is switched off.
09:38The process of a forced braking is as follows.
09:43The driving locomotive leads the locomotive magnet with its power field
09:49over the track magnets, which are particularly switched by the stop signal.
09:55The power fields of the locomotive magnet
09:58hit the track magnets, which are tuned to the same number of vibrations.
10:05Now, from the track magnet,
10:09a reflection of the magnetic power field occurs,
10:13which causes a power weakness in the locomotive current circuit.
10:36As a result, the anchor of the magnetic switch falls off on the locomotive.
10:44The brake valve, which releases the forced braking, opens.
10:50The locomotive magnet now carries not one, but several,
10:56namely, different windings.
11:01As a result, several power fields can be radiated at the same time
11:06with different large number of vibrations.
11:10For example, with 500, with 1000, with 2000 Hz.
11:15By correspondingly tuned track magnets,
11:19several different effects can then be transferred from the locomotive in the simplest way.
11:27With 500 Hz, the already treated, immediate forced braking.
11:35With 1000 Hz, the inspection of the vigilance of the locomotive driver at the stop signal.
11:44After passing a stop signal in the warning,
11:48the locomotive driver must press a vigilance button within a certain number of seconds
11:54if he wants to prevent a forced braking.
11:58With track magnets tuned to 2000 Hz,
12:03the allowed speed is checked.
12:08The 2000 Hz relay is connected to a speedometer on the locomotive.
12:16Only when the speed specified at this point is exceeded,
12:22forced braking occurs.
12:24Acoustic signals and special registration facilities
12:28constantly teach the driver about the operational readiness of the entire safety system.
12:36In addition to this inductive train safety procedure,
12:41the Deutsche Reichsbahn also conducts experiments with a procedure
12:46that is primarily based on optical interaction.
12:51With the optical train safety procedure.
12:56In the case of optical train safety, the locomotive carries a metal housing at the front of the right buffer bowl,
13:04the so-called OPSI indicator.
13:11In the housing there is, among other things, a light bulb
13:18which, through a lens in the lid of the indicator,
13:22radiates its light almost vertically upwards,
13:27of course also during the day.
13:31Installed in protective housing and attached to signals or special masks,
13:38special mirrors are attached along the railway track.
13:43These are the so-called triple mirrors.
13:56These mirrors have the property
14:00to radiate the rising light exactly back to the starting point,
14:07even when the locomotive fluctuates.
14:12In reality, two light bulbs are thrown back from the triple mirror,
14:20whereby a special mirror grinding is achieved
14:25so that the light bulb appears a few centimeters to the side of the light exit opening on the indicator.
14:36Inside the indicator there are, among other things, two light-sensitive cells.
14:42These cells are connected to electrical lines leading to a metal housing
14:48that is attached to the locomotive at the driver's cab.
14:52Here the amplifiers are most noticeable,
14:55as we know them from our radios.
14:59The OPSI mirrors on the track are mechanically connected to the signals.
15:04They can therefore be rotated by placing the signals around their right axis.
15:13With the mirrors attached to their own masts,
15:17the rotation can also be done remotely.
15:20Through the rotation of the mirror,
15:24the reflected light can reach either one or both light-sensitive cells in the indicator.
15:35If the main signal is set to stop,
15:39the so-called stop cell in the OPSI indicator will be illuminated by itself.
15:51This creates a current shock in the line.
15:58This is amplified by the amplifier tubes.
16:03A relay is now operated here,
16:06which interrupts the circuit of the brake magnet.
16:11The brake valve opens,
16:14the compressed air escapes
16:17and the compressed air enters.
16:22If the main signal is set to stop,
16:25the mirror is set in such a way
16:28that the reflected light only hits the stop cell.
16:33In this case, the locomotive driver has to operate a vigilance button
16:39and measure the speed of the train
16:42if compressed air should not enter.
16:46Even when the signal is set to start,
16:49an effect occurs.
16:52Both cells are illuminated here.
16:56A alarm is sounded
16:59and the locomotive driver is shown the direction in which he is working.
17:07With the compressed air at the main signal alone,
17:10not every danger is eliminated.
17:12Since the increasing speed of the trains
17:15also increases their braking distance considerably,
17:19if a train is to come to a stop at the main signal,
17:24its speed must be measured accordingly beforehand.
17:31The surveillance of the train speed
17:34is achieved by corresponding mirror settings
17:37at any point in the line.
17:40A speedometer installed in the headlights
17:44is connected to a display.
17:48The display shows the path of the reflected light from the mirror
17:54to the stop cell
17:58as soon as the allowed speed is exceeded.
18:02The self-operating train security systems
18:06meet the latest requirements of today's state of technology
18:11that can be met for safety on the rail.
18:16Now I come to safety on the road
18:20as far as rail and road are concerned.
18:24I mean the crossings in rail height
18:28of which we have about 70,000 at the Reichsbahn.
18:33In 1935, 1,300 accidents occurred on these crossings.
18:43577 people were injured,
18:48of which 177 were killed.
18:52Almost 80 percent of these accidents
18:56had to be booked on the vehicle's account.
19:00All crossings that lead over main lines
19:04as well as the traffic-rich or confusing crossings
19:08over side lanes have barriers.
19:12Since 1928, the railway administrations have set up
19:17crossings at the crossings
19:20to draw the attention of the fast-moving road vehicles
19:24to the point
19:27where they have to stop when approaching a train.
19:31A lying cross whose lower legs are shortened
19:35means crossing with barriers.
19:41A lying cross with equal-length legs means
19:45crossing without barriers over a one-track track.
19:54A lying cross with equal-length legs means
19:58crossing without barriers over a one-track track.
20:03The red flashing warning light
20:06that you see now at the crossing in connection with the crossings
20:10announces the approach of a train.
20:13This warning light has been added to the crossings
20:17at individual unbound crossings since 1929
20:21when increasing road traffic required it.
20:25When the warning light is white and flashing slowly,
20:29the crossing is free.
20:31The latest innovation is the crossing data
20:36that is set up on both sides of the road
20:40from April 1, 1936,
20:43in front of all crossings of the Reichsstraße.
20:49They are reproduced in the pre-signal barks.
20:53On each side of the road there are three barks one after the other.
20:58The first, 240 meters in front of the crossing,
21:02with three oblique red stripes of glass backlights.
21:07A warning sign is connected to this first bark
21:11that shows a gate in front of crossings with barriers.
21:15At crossings without barriers, on the other hand, a locomotive.
21:2080 meters further follows a second bark
21:24with two red stripes of glass backlights.
21:28And again 80 meters further the third bark with one stripe.
21:34We are now approaching a crossing without barriers.
21:39The red flashing warning light
21:42finally shows us the name of a train.
21:46We have to stop.
21:50Their main task is to fill the crossing barks in the dark.
21:56The light of the traffic lights is reflected
22:00from the backlight stripes,
22:03which consist of the well-known cat's eyes.
22:08We are warned.
22:10The first bark carried the warning sign.
22:14So now comes a crossing with barriers.
22:20So you see, gentlemen,
22:23how in the fight against the danger of accidents
22:26new facilities are constantly being created
22:30that all pursue only one high goal.
22:34Safety on rails and roads.