Shaft signal system
A shaft signaling system , also known as a shaft signaling device, is a technical device on a shaft which is used for communication between the haulage machine operator and the shaft operator . Already in early mining, mechanical signaling devices were used to communicate between the miners working in the shaft and the Göpel foreman .
Basics
When operating a shaft conveyor, it must be possible to communicate safely between the machine operator and the shaft operator. A simple option is to use acoustic or optical signals. Acoustic signals have the advantage that they can be perceived by a person without the person having to be particularly prepared for the signal. Underground it is often very loud at the shaft too, so signals can only be understood if they are loud enough. Signals with a shrill tone also stand out clearly enough from the noise level . The shaft signaling system enables communication between the filling point, the suspended bench and the conveyor operator. In addition, there is the possibility of communication from any point in the shaft from between the shaft fangs and the conveyor machinists, z. B. during shaft work or manhole drives.
Signaling equipment
In the case of day shafts, the shaft signal systems must be operated electrically. The individual devices must comply with the electrical regulations. In hard coal mining it is necessary that the devices are not only protected against contact but also protected against firedamp . The individual operating devices must be clearly arranged so that there is no confusion during operation. It must be possible to operate the signaling devices from a safe location from which the conveyor or cable car operations can also be easily observed. Various devices are used as signaling devices that enable signals to be emitted, transmitted and received. There are devices for impact signals, for ready signals and for emergency signals. There are also facilities for oral communication if necessary.
Impact signaling devices
Pull switches or push-button switches are used as signal transmitters for the impact signals. Impact alarm clocks serve as acoustic signal generators, these are alarm clocks that are equipped with a clapper anchor and only strike the bell once with each current flow. This makes it possible for the signals to be issued in quick succession and also to sound clearly. So that only the impact signals from the bottom to the conveyor machine operator where the conveyor cage is located, the signaling is locked by a bottom- dependent signal blocking. This is done by special switches on the depth indicator or on the speed controller of the hoisting machine . In the case of double-ended conveying, the impact signal must first be given to the suspended bench and from there to the conveying operator. The person attacking the hanging bench has the opportunity to use an impact signal to ask questions to the attackers who are on the soles. In single basket operation, the impact signal is sent directly to the conveyor operator. He can also ask questions via an impact signal. All impact signals can be heard at every stop.
Ready-made signaling devices
When operating using the ready-to-use signaling device, the signals are not first sent to the stopper on the hanging bench and from there to the conveyor operator, but the signals are given independently of the other stops. The signal is entered from each stop using a push button switch or pull switch. The finished signals of the individual stops are saved after they have been entered. As a control, the respective finished signal is indicated by a lamp at the individual stops. Only when all the finished signals have been given is the finished signal (execution signal) automatically forwarded to the conveyor operator. This signal is an optical and acoustic signal. The optical execution signal is given by a ready-made lamp and the acoustic execution signal by a rattle alarm clock. After the haulier has released the brake, the stored finished signals are deleted.
Distress signal
An emergency signal that is activated via an emergency switch is provided for dangerous situations . After pressing the emergency switch, a very loud emergency horn sounds. When the emergency signal is triggered, all saved ready-made signals are deleted. If a ready signal is given when the machine operator has already released the brake on the hoisting machine, an emergency signal must also sound. The emergency signal will also sound if a stored ready signal is not deleted. The emergency signal sounds both on the operator's stand and on all stops. When the emergency signal sounds, the carrier operator must immediately stop the carrier.
Sack hammer
Until the introduction of electricity, the shaft hammer was the only means of communication between the attackers and the haulers for a long time. It is operated by a cable that runs the entire length of the shaft and extends into the machine room or the suspended bench. The rope activates a clapper that strikes a metal plate or bell and thereby generates an acoustic signal. In shafts with great depths , the shaft hammer can only be operated very slowly and with difficulty. For this reason, the shaft hammer has been replaced as the main signal system by electrically operated impact or ready-made signal systems and has been pushed into the role of an emergency signal system. Today it is only used for manhole visits or work. So that the shaft hammer rope cannot be operated from the stops and only by the shaft tails on the cage, it is passed through a pipe in the area of the stops. While mechanical manhole hammers were used in the manholes in the past, electric manhole hammers are used today. To do this, the rope is attached to a pull switch and when it is actuated, it emits a signal via the electrical signaling device. In addition to this electromechanical manhole hammer, there is also the electronic manhole hammer. This shaft hammer consists of an impact signal generator that transmits the signal via a radio transmission system. The shaft hammer must work in the shaft over the entire depth. If the shaft hammer operating mode is switched on, no signals may be possible from the stops apart from the emergency signal.
Optical signals
In addition to the acoustic signals, additional optical signals are attached to all underground stops and on the hanging bench. Light fields are used to indicate operational readiness. In addition, the respective operating mode is displayed by means of optical signals. Every miner can see immediately whether the system is in the operating mode of rope travel, shaft hammer operation or goods transport and behave accordingly. Different colors are used for the visual signal displays. Red lights are used for warning and fault lights. White lights are used for operating states and green lights are used for finished lights or gate lights. The light fields must be labeled according to their function, with the exception of lights that are unmistakable, such as gate lights.
Signal tower
All shaft signaling devices are brought together in the signal tower at the operator's control station. This signal tower consists of a column-like switch cabinet. In the signal column there are several light fields for the individual operating modes, the signal devices of the signal devices of the haulage operator control station and the shaft signal recorder. All signals, the speed of the conveyor cage and the brake actuation are displayed on the shaft signal recorder. In addition, the signals between the soles and the hanging bench are recorded in chronological order. With the shaft signal recorder, all processes can also be checked retrospectively and, in the event of an accident, can be used to clarify the cause of the accident.
The signals
Simple signals are used for communication. In German mining, a distinction is made between execution and announcement signals: Execution signals are standardized throughout German mining, the announcement signals can be different between the individual mines . In the mining of the GDR, the signals were uniformly defined and still apply in the state regulations of the new federal states. The regulations of BVOS NRW apply accordingly in most of the West German federal states.
| Number of strokes | meaning | ||
|---|---|---|---|
| West German BL | East German BL | ||
| 1 | Stop! | Execution signals | |
| 2 | On! | ||
| 3 | Hang! | ||
| 4th | Slowly! | Announcement signals | |
| 4th | 5 | Rope ride | |
| 6th | Self-drive | ||
| 3 + 3 | 4 + 4 | Free basket! | |
The execution signals are stop , open and hang . One beat is given for the “stop” signal, two beats for the “open” signal and three beats for the “hang” signal. The reason for this regulation is to give the stop signal in particular the shortest signal. The "Halt" signal is also given in the event of danger and there must not be any delay due to signals that are too long. Inadequate signaling or in the event of a fault, if only one blow comes through, there can be no danger, because the machine operator does not move the hoisting machine in the event of a blow.
Announcement signals are signals that announce a certain specialty in operation. These signals are often supported or completely replaced by optical signals. The announcement signals are still regulated differently in the mining ordinances. For example, according to the Thuringian BVOS, the rope journey is announced with five strokes. This regulation also corresponds to that in the other four new federal states. According to the BVOS of the state of North Rhine-Westphalia, the rope journey is announced with four strokes. The “basket free” signal is also regulated differently. In the Thuringian Mining Ordinance, four hits are considered “free basket” twice. In the BVOS of NRW, the "basket free" signal is announced by two three blows.
In the case of self-propelled rope travel, the number of people on the basket is limited compared to the sling rope ride. Six people plus those entitled to drive themselves are common.
In response to the “cage free” signal, the machine operator pulls the cage away from the stop or the suspended bench so that the shaft gates cannot be opened.
Verbal communication
In certain situations, verbal communication between the shaft operator and the machine operator is often required. In older manholes, a speaking tube was used at shallow depths of up to about 100 meters. Electric or electronic telephones (shaft telephones) are used today. These telephones enable verbal communication at any time between all the hoists of a hoisting tower located on the shaft and the machinist of the respective hoisting machine. To avoid confusion, the call signals of the telephones must be clearly different from the individual and emergency signals.
Special AGV systems are used for verbal communication between the manholes and the machine operator during manhole visits or manhole work. These systems are used for conveyance telephony and also enable verbal communication while the basket is moving. There is a button for signaling that is monitored for contact sticking.
Individual evidence
- ↑ a b c d e f g h i Technical requirements for shaft and inclined conveyor systems (TAS). Verlag Hermann Bellmann, Dortmund 2005
- ↑ Signals in mining: www.schneeberg.de ( memento from January 6, 2015 in the Internet Archive ) (accessed on March 14, 2016).
- ↑ a b c d e f g h i j k l m Carl Hellmut Fritzsche: Textbook of mining studies. First volume, 10th edition, Springer Verlag, Berlin / Göttingen / Heidelberg 1961
- ^ E. Gerland: Textbook of electrical engineering. Published by Ferdinand Enke, Stuttgart 1903.
- ↑ a b c Thuringian Mining Ordinance for Shaft and Inclined Conveyor Systems (ThürBVOS) of November 1, 2004
- ^ Shaft signaling device: Association for Mining, Industrial and Social History Dorsten ( Memento of October 6, 2013 in the Internet Archive ) (accessed on July 26, 2011).
- ^ Carl Hellmut Fritzsche: Mining Studies . Textbook of, with special consideration of the coal mining industry. Tenth, completely revised edition. 1st volume. Springer, Berlin / Göttingen / Heidelberg 1961, p. 521 .
- ↑ Collective of authors: Expertise for potash and rock salt mining . second improved edition. People and Knowledge, Berlin 1953, p. 251 .
- ^ Ropeway regulations for the research and teaching mine ( Memento from January 19, 2015 in the Internet Archive ) (accessed on March 14, 2016).
- ↑ a b Mining Ordinance for Shaft and Inclined Conveyor Systems (BVOS) of the state of North Rhine-Westphalia of December 4, 2003
Web links
- Mining Ordinance for Shaft and Inclined Conveyor Systems (BVOS) / IV. Operation /. District government Arnsberg, December 4, 2003, accessed on May 5, 2013 .