The usefulness of the impressioning technique. How does impressioning work? A discussion about impressioning, by Harry Sher. Ford Galaxy wafers, showing indication of picking and decoding HPC and other produce a complete line of axial picks and The Easy entrie profile milling machine can produce blanks.
Discussion of endoscope and borescope. The John Falle lever decoder system. Bypass of laser track or sidewinder locks. A discussion of reading the belly of a lever.
Forensic implications of the bypass of lever locks. Forensic implications of picking or decoding the Abloy lock. Pick tools for the sidebar lock, courtesy of Harry Sher. Courtesy Ian Bauchop. Confined space with one deadlock and two sliding bolts. External steel grilles protection windows; Internal - Inward opening solid timber door. Attack made with chain saw on hinge side.
Cylinders can be forcibly removed by applying torque and destroying internal setscrews. The setscrews can also be removed during business hours to allow the cylinder to be unscrewed at a later time.
A wrench attack on cylinders can be very effective. Sigma analysis of the Kibb interlocking strike plate, with Ian Bauchop. Demonstration of different forced entry techniques on doors utilizing the Kibb interlocking strike plate design.
Forensic evidence of forced entry. Opening a padlock by bouncing the locking dog. Courtesy of Ian Bauchop. In this figure, peeling was accomplished from the corner using a cold chisel. A classic peel attack is shown right. The result of pounding of components. Example of punching. Pressure was applied to the hinge side. This was a pound attack. The door was pounded with many hits. In the middle picture, an inept attempt to open the safe by cutting through the side.
Attack using a torch where there was obviously no knowledge of where to cut. In the photographs, the lock box is burned out. Incorrect tools were utilized on the side of the safe. The thermic lance develops high temperature and can be utilized virtually anywhere. This is a rear view, with the lock case removed. LSS Steve Mattoon on the use of explosives to gain entry. Hinges and forensic evidence.
Courtesy Don Shiles. Case example: removal of sliding glass door. LSS Ross Anderson on biometrics. Chapter 40 Alarm Systems Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure a Alarm system flow chart b Alarm system flow chart Analog alarm circuitry Magnetic contacts Magnetic contacts Banknote contacts Pressure mats Trip wire contacts Bolt contacts Striking plate magnetic trip contact Placing foil on glass Electrically conductive metal foils Alarm glass Security alarm glass Passive glass-breakage detector Active glass breaking detector Piezoelectric sensor within a seismic detector Seismic detector readings Photoelectric monitoring system.
Original dial-up alarm reporting device Exterior intrusion sensors Exterior sensor applications model Interior sensor application model Interior intrusion sensors Early alarm transmitter and receiver for central office Magnetic switches in different configurations Wires can be embedded in window screens and act like window. The scope of this beginning chapter shall be to present a summary and chronology of major technical achievements of locking mechanisms during the past four thousand years.
Particular emphasis will be placed upon developments since the beginning of the nineteenth century. The historical development of safes, combination locks, and lock picking are topics presented elsewhere, but not covered in this chapter. Lock makers have demonstrated tremendous intellectual energy, cleverness, and skill for over forty centuries. These craftsmen would continually improve upon designs, playing a never-ending game of "security chess" with their opponents; the burglar.
As each new feature was designed into a lock to frustrate methods of bypass, a resourceful locksmith, engineer, or criminal, in order to circumvent the last innovation, would develop new techniques. It is difficult to fathom the problems presented by early security needs.
Consider living thousands of years ago as a wealthy landholder, merchant, or banker. You have land holdings and have amassed many possessions of great value. Perhaps you are a merchant, jeweler, or moneylender. How do you protect your valuables, your castle, and your family from robbers and thieves? In the beginning, there were no vaults, electronic alarm systems, safe-deposit boxes, high-security locks, or other devices that could guarantee security.
Extremely inefficient yet effective, the hired watchmen together with constant vigil provided the only real security to protect your possessions from the thieves and robbers of the day. At some point, the local blacksmith is consulted, and asked if there is a way to provide better security through fortified enclosures and secret fasteners or locks. So, the blacksmith sets to work on the problem, apparently in many different parts of the world simultaneously.
Such a demand for security was experienced that a special guild would emerge for those who dealt with such problems: locksmiths. Remember, there is no machine shop, no security industry, nor any high-security locks or enclosures.
The only materials are wood, brass, bronze, and iron. There are no factories, sophisticated metallurgy, or machinery to make the small and intricate components found in modern locks. There was essentially nothing to draw from in the blacksmith's experience to solve the problem of protecting people and their assets. There is no history of technological developments. It is the beginning.
So how did we arrive at the end of the twentieth century with such an array of simple to highly sophisticated and secure locking devices and enclosures designed to protect people and their assets.
Chapter 1, then, traces the slow evolution of the lock through four thousand years to present state-of-the-art designs. The organization of the chapter attempts to present the logical steps that must have occurred in the development process.
In order to provide the reader with the rich history and perspective of the development of the modern lock, the author has revised two major works of the nineteenth century that are considered the source reference works on the subject of locks, safes, and security.
This is one of the most comprehensive and authoritative works on locks and safes, providing a chronicle of innovations and developments in locks and safes from their inception. Hobbs and edited by Charles Tomlinson in This book provides another chronicle of the technology of early locking devices, and traces the conceptual changes in design as relates to security.
Interestingly, both of these individuals were American lawyers. Hobbs is credited with having been the first person to bypass the Bramah lock, produced in London. This feat, as will be described subsequently, set the stage for a race for higher security and new designs in locking mechanisms at the Great Exhibition of in London. That race continues today.
Around B. It is unknown when the original mechanism that could fairly be described as a lock was really created.
It appears that the first reference to locks was noted by Joseph Bonomi in Ninevah and its Palaces. This described one of the frescos discovered in the ancient biblical city of Ninevah that showed a picture of a lock. The fresco was painted by an Egyptian artist, which provided evidence of dating to that era. The remains of an actual lock, corresponding to the fresco, were found in the ruins of a sumptuous palace near Ninevah.
It is believed that this is the oldest lock in existence. The reference in Bonomi's book described a lock as having secured the gate of an apartment in one of the palaces near Ninevah. He wrote that "the gate was fastened by a large wooden lock, the wooden key with iron pegs at one end to lift the iron pins in the lock, being so much as a man can carry.
The reference clearly described the Egyptian pin tumbler lock. There are a number of references to locks and keys in the Bible, leaving no doubt that the lock as we understand the concept today, has existed for at least forty centuries. It is logical to believe that primitive man's treasures were initially buried or hidden in caves, hollow trunks of trees, or other physical locations that could be easily created or exploited. Once doors or other solid surfaces were employed to secure a perimeter, the next obvious step would have been the capability of locking the door in place.
In the beginning, of course, there were no latches as we understand the term today. It appears that the Greeks, who developed crude wooden fastening devices on the inside face of the door, conceived the initial concept of using bars and boltwork.
Realizing that one of the drawbacks of the Egyptian lock was its vulnerability to attack, the Greeks placed their locks on the inside of the door but provided access to the mechanism from the outside through a keyhole. Although it is unknown whether the Greeks took these ideas from the Romans, they are credited with the concept of interior locking mechanisms, operable from either side of the door. They utilized a massive bolt with a large sickle-shaped key.
It had a semi-circular blade, measuring a foot or more in diameter, and a long handle that tapered to a blunt point. The Greek "keys" would often be inlaid with precious metals, for locks were utilized by the wealthy. The major problem with the Greek design was that there were very few different key patterns available. Thus, there was little security against bypass through the use of primitive "skeleton keys.
The development of the Greek and Egyptian door locks appear to have occurred at about the same time. Interestingly, Greeks are credited with making simple bolt-locking mechanisms available to the middle class, while the Egyptian pin tumbler locks were affordable only by the wealthy. In the days of Homer, doors were tied shut with intricately knotted ropes. They were so cleverly laced that only the owner could find the correct method of unknotting them.
Moreover, the superstitious beliefs of the times insured that no one would dare to tamper with the ropes, lest a curse fall upon them and their families.
Some evidence suggests that the first mechanical barring of a door was by a cross-beam that was dropped into sockets or by sliding staples affixed to the door. It is theorized that a vertical pin was probably dropped into a slide to secure the beam. If the beam were to be placed on the outside of the door, then the locking pin would have to be hidden, yet retained and accessible through a hole in the beam or staple. In order to make the lock function from outside, the cross-beam was shortened into a long bolt which was made hollow to allow the pin to be reached.
To move the bolt, a key was fashioned that had pegs matching the hidden pins within the bolt. A variation of this early lock was a configuration wherein the pins were reached by holes in the staple, not through the bolt.
This design was very popular and was utilized in different parts of the world, including Scandinavia, the Faro Islands, Africa, and the Balkan states. There was a principal difference between the Greek and Egyptian lock. In the Greek mechanism, the key moved pins into position to allow release of the bolt, which then was moved back by hand. In the Egyptian lock, the key actually was used to withdraw the bolt.
The next improvement was mounting the bolt on the inside surface of the door. Keys appear to have been sickle-shaped pieces of iron, apparently put through a hole in the door and used to push or pull a retaining pin. The key would compress the spring to open the lock; the bolt could then be withdrawn. The Greeks are credited with the concept of interior bolt mechanisms accessible through a keyhole. It is interesting and curious that they never applied their intellectual abilities to the design of locks, as did the Egyptians and Romans, in spite of the great academic, political, and scientific achievements of Athens.
A mock-up of the original Egyptian lock, produced by the British Museum, London. This replica shows the interaction of the protruding pegs with the internal pins. The Egyptian craftsmen are responsible for conceiving one of the principles upon which all modern lock designs are based; the pin tumbler. Their invention would ultimately lead Linus Yale to perfecting and patenting the modern version of that mechanism.
The real genius of the Egyptians was in conceiving double-acting detainers that had to be lifted to the correct level in order to create a shear line to allow the lock to operate.
Their clever innovation set the stage for the development of every mechanical locking mechanism in existence today. Yale would base his lock design upon this principle, with the further refinement that the detainers or pin tumblers could not be lifted too high or too low: they would have to be raised precisely to the correct height.
The Egyptian lock was attached to the outside surface of the door. First made of wood, later models were constructed of brass and iron and ornamented with inlaid pearls, gold, and silver. The locks measured two to three feet in length. The mechanism was housed in a rectangular container into which the bolt would slide. Inside this hollow container was placed several irregularly shaped wooden pegs or pins, usually numbering from three to seven.
They were arranged in random patterns and were set to move up and down. When in the locked position, the pins rested half in the bolt and half within the main lock housing. Examples of different approaches to the original Egyptian pin tumbler design. These locks have been gathered from different countries, and demonstrate that the idea of using pins or pegs to secure a moving bolt or locking piece was not unique to any one society, although the Egyptians are credited with the initial concept.
These exhibits are on display at the Science Museum in London. The key for the Egyptian lock was also two to three feet in length and had wooden pegs inset in a vertical position at one end. These pegs were placed on the key to match the pin positions inside the lock. The function of the internal pins was to hold the bolt solid in the lock housing.
Keys came to represent a sign of spiritual and temporal power. They symbolized man's ability to gain access to those things he considered to be of greatest significance. The pin tumbler concept was widely imitated, and even to this day similar locks are occasionally dug up in places as remote from each other as ancient Assyria, Scotland, Japan, and America. Apparently the skill and techniques of the ancient lock makers, as well as the fundamental soundness in design, survived the fall of great empires and even time itself.
The craftsmen of the ancient Roman Empire are credited with a number of major advancements in the development of the lock. Recognizing basic defects in earlier devices, they took the best of the Greek and Egyptian designs to produce sophisticated locks, as well as the revolutionary warded design. They also popularized padlocks, originally developed by the Chinese. The Roman artisans were familiar with working in metals; thus they dispensed with large bolts and keys. They recognized that smaller keyholes made locks more difficult to pick.
Although keys for the Greek and Egyptian locks were quite cumbersome, the Roman counterpart was small, ornate, and intricate. Evidence of the sophistication of Roman lock design can be found in the ruins of the ancient city of Pompeii which was engulfed by the volcano Vesuvius in 64 A. One of the significant finds in the lava of Pompeii was the discovery that keys were required to rotate within locks less than to actuate the bolt.
Thus, it appears that the Romans were the first to introduce a spring-loaded bolt into their locking mechanism, thereby eliminating the problems encountered in gravity-locking devices. Although the Chinese and Near East peoples developed the padlock, the Romans are credited with having popularized it. They made it a practical device, even going so far as to produce the key as a part of a finger ring for convenience in carrying by the owner. The fact that the Romans had no pockets in their togas may have inspired their locksmiths to devise keys that were small and inconspicuous.
This mock-up of a warded lock demonstrates its principle of operation. The key is allowed to rotate the bolt only when the obstructions are cleared. This and the following illustration were produced by the Science Museum, London. While Roman artisans knew that their locks provided greater security, they continued to seek refinements in the mechanisms to frustrate the conventional forms of bypass.
The origin of the warded lock is obscure. It is likely to have been invented by the Etruscans in northern Italy, although recent evidence indicates that the Greeks also knew of the concept. Regardless of its origin, the warded mechanism was perfected by Roman artisans and was to remain the most popular design until the middle of the nineteenth century. It is still found in wide use today. Wards were a logical extension of the primitive alteration of the shape of a key to frustrate entry into a lock.
Some ingenious lock maker discovered that he could place a series of obstructions in the path of a turning key and thus make the lock secure. Only the correct key with the same spaces on its body could pass the obstructions.
Thus, the essential principle of the warded lock was to provide one or more internal obstructions to block entrance and rotation of all but the correct key. The incorporation of wards added a completely new dimension to security against picking and led the way for the production of many different shapes and sizes of locks. Craftsmen continued to improve upon the mechanism, making the keyway and ward pattern more intricate. Then, when this was not enough, they began to use multiple locks for greater security.
As an example, it was reported that in , Queen Isabelle of Bavaria called her locksmith to secure the apartment where the ladies-in-waiting were quartered. The doors were fitted with locks that required five different keys to gain access.
The Middle Ages followed the fall of the Roman Empire. While scientific achievements were few, locksmithing flourished during this period in history. Warded locks were now not only complex mechanisms but became works of art.
Prestige and respect was accorded those with the most intricate locks. This is a warded lock that was produced between the fifteenth and eighteenth century. Note that multiple keys were required. These were the days of castles and knights, of robber barons, and of monasteries containing books and manuscripts of great learning from ancient days.
Security took on new and more urgent dimensions. The warded lock had been designed to perfection, and yet it was not secure enough. The demand for more security increased to match the accumulation of wealth. The late eighteenth century produced the next significant refinement of locking mechanisms: the lever concept.
This replica is made from a lock preserved in Pompeii after the eruption of Mt. Vesuvius in in A. It closes with a hasp. From the time of the Romans until the end of the eighteenth century, security was based upon fixed obstructions and elaborate keyholes, fine slits, perforations, and intricate keys.
Falling pins, invented by the Egyptians, were forgotten. No other methods had been invented to put more security into the locks. Towards the end of the seventeenth century, traditional sliding and pushing of keys gave way to the concept of turning. Keys would rotate around a pin or slide through a keyway. As developments progressed, many different key designs emerged, incorporating both art and utility. In , Robert Barron developed a new and radically different locking mechanism. Over the next two hundred years, many modifications to the Barron lock would be introduced, as well as completely new and fundamentally unique designs.
Because of the many different advances since , a chronological summary of important inventions, beginning with Robert Barron, is presented in the remaining portion of this chapter.
A detailed treatment, examining the significance of each of these major developments, will be found at the beginning of the chapter relating to the corresponding basic locking mechanism. This format will allow the reader to logically trace and understand the changes made to each type of lock and how various designs evolved.
With the exception of the Egyptian pin tumbler design, most locks had relied upon wards prior to the lever principle. The Barron lock, first introduced in England, was based on a completely new locking theory: the double-acting lever tumbler. It was probably the most significant development since that of the ancient Egyptians.
Through many refinements and modifications, the lever lock would become one of the most popular mechanisms in the world to this day. Originally, the lever was a form of catch. Until raised by a key, it would normally hold the bolt in a fixed, immovable position. In the first lever locks, the key merely had to lift a single spring from a notch in the bolt and then force the bolt forward. The height of the lift was not important, provided that the notch was cleared.
The Banbury wooden locks employ this principle. The bolt of the Barron lock had a square-cut notch, called a gate. The key would lift all the levers until the stumps cleared the gates, allowing the bolt to slide into a locked or unlocked position. If any of the stumps were raised too high or not high enough, the bolt could not move. The lever principle was a great improvement over wards, because it was believed that wax could not be used to determine precise details of the mechanism.
This was true, at least for a few years. Levers offered the first real security against picking because the lever not only was used to hold the bolt but to block its movement until the correct key was used. Several levers were employed, thus eliminating the use of skeleton keys that had defeated all security in the earlier warded lock. Essentially, all lever locks for the next two hundred years would adopt a design based upon the original Barron concept.
Each were based upon the idea that a moveable, pivoting lever should have a square gate cut into its end opposite the pivot point. When lifted to precisely the correct height, it would allow a stump to enter the gate, and thus permit the bolt to laterally move. Today, locks of seven or move levers can provide extremely high-security against picking and other forms of bypass.
In this exhibit, the levers are a rest; the bolt is locked in position and is blocked from movement. Note the stump is floating between the gates. The Queen of England recognized Bramah for its excellence in the manufacture of locks.
In , Joseph Bramah was the first to receive a patent for a lock in which the key did not actually reach or make direct contact with the bolt.
Rather, it acted through an intermediate and intricate slider mechanism. This design allowed the lock to be physically small, yet secure.
The Bramah key was a tube with narrow longitudinal slots cut in the end. Depressing the key into the lock would cause a number of sliders to align at a shear line. The Bramah design resembles, in some respects, the modern axial pin tumbler of Chicago Lock Company and others. Interestingly, Bramah's invention initially found no commercial acceptance. For many years, the pickproof lock, on display in the window of the Bramah Lock Company at Piccadilly, in London, remained unopened; the reward for picking this lock uncollected.
Seventy-five years later, a subsequent version of this lock was to become the focus of a contest at London's Great Exhibition of and a catalyst for competition in the development of pickproof locks. For almost two hundred years, the name Chubb has been associated with quality lock manufacturing, design innovation, and many revolutionary patents, including the Detector lock.
Chubb was the name of a famous inventor who originally founded the company in , after the immediate commercial success of his Detector Lever Lock. Charles Chubb and his younger brother, Jeremiah were born in England in and respectively. The Chubb's originally worked as iron mongers in Portsea, England, building ships. In Jeremiah patented the Detector lock, which was an immediate success. The brothers then opened a lock factory in Wolverhampton the same year to produce and market the product.
Since that time, the company has grown to be one of the most highly respected lock and safe makers in the world. At the end of the nineteenth century, their products were so respected that in the Chinese colonies the natives would refer to "Chubby pot of jam" or "Chubby pair of trousers," meaning that they were of the highest quality. The Chubb Safe Company, still headquartered in Wolverhampton, today has offices throughout the world.
The firm manufactures a broad range of security products, including safes, lever locks, and electronic alarm systems. They have received numerous awards for design and production excellence, including recognition by the Queen of England for their contributions.
Innovation, based upon research and development, has been the hallmark of the company. Chubb, for example, recently was the first to receive a patent for an all-plastic fire and burglary-resistant safe, called the "Planet.
The Detector was a mechanism with a slightly different lever design than found in the earlier Barron lock. Chubb conceived of a different configuration, wherein the gates formed part of each lever, in contrast with the Barron lock, where the gate was actually part of the bolt. This significant enhancement remains in use to this day.
The essential element of the Detector lock was its ability to show if any attempt had been made to pick open the mechanism. This feature, coupled with the capability of completely disabling the operation of the levers once an unauthorized attempt to pick or use an improper key was made, provided a high level of security and confidence to the owner. Chubb made many improvements in the design of the lever lock, including the introduction of a curtain that surrounded the keyhole internally.
This enhancement would revolve with the key, making picking impossible. While refinements in the lever lock were being made, there were also efforts to increase the security of the combination lock sometimes called letter, number, or permutation locks. These made their appearance during various stages of the world's history, dating back thousands of years to early China. Their application was usually confined to padlock designs and offered very little security against opening by "feel" or manipulation.
They were never popularly accepted as secure locking devices until modern machine methods achieved high tolerances. In fact, until the middle of the nineteenth century, they were mainly looked upon as locks of convenience only. Criminals, especially in America, determined that the simplest way to obtain the contents from the bank vault was to kidnap the cashier or bank manager and force him to open the safe.
A Scottish inventor, William Rutherford, developed a combination lock utilizing a disc with a notch cut in the side, to be driven by a clock. Rutherford placed a circular stop-plate at the rear of the lock. This prevented the operation of the bolt until the plate had rotated to a certain position, which was controlled by the timing mechanism.
The modern version is simply a variation of this design. The introduction of the time lock revolutionized the security of safes and vaults. The original Rutherford invention did not receive much attention until an American, James Sargent, of Rochester, New York, improved upon the design in Sargent made the use of these locks practical. Because of the introduction of the Sargent design, combination locks gained wide acceptance in the United States during the second half of the nineteenth century.
An early example of another time lock developed by Pillard. The Parsons balanced-lever lock was significant because of the change in design of the levers. These were set to pivot in the middle, rather than at one end. The lock was designed so that if any lever were raised too high, as with a false key, it would hook into the bolt, thereby becoming immobilized.
This lock was produced with seven levers and provided an innovative design. The Newell Parautoptic lock was shown at the Great Exhibition in It was invented by Robert S. The word parautoptic, taken from the Greek, means concealed from view. The lock was designed so that it was almost impossible to reach the working parts from the keyhole. By utilizing a double set of lever tumblers, one acting in sequence upon the other, and a rotating plate that would block the tumblers from inspection, the lock was virtually impossible to pick.
In a further innovation, the combination of the lock could be changed at will by altering the relative positions of the parts of the key bit. The key is comprised of fifteen separate segments that are interchangeable and which controlled the derivation of the combination. This was a simple four-lever lock, following the original Chubb design, with some modification. Alfred Charles Hobbs, an American locksmith, is also credited with being the first to pick the world-famous Bramah lock.
A variation of the Chubb lock was introduced in which featured four levers formed in the shape of a wheel, mounted on a central pin and enclosed in a moveable barrel. The barrel formed the true keyhole that was offset from the key. The design made it impossible to insert a picking tool to reach the levers. To increase its pick resistance, the inventors also required that the key turn the moveable barrel before the stump on the bolt could enter the gate.
Until the eighteenth century, lock designers appeared to be more concerned with creating works of art than of security.
Chubb, Bramah, Newell, Parsons, and many others improved upon designs and received patents for concepts that can be found in use today. A public rivalry developed between inventors, in a constant quest for greater security against picking. Public contests were held as new inventions were introduced. The masters pitted their lock-picking skills against one another in an attempt to defeat each new innovation. This intense competition was responsible for many of the significant improvements in certain lock designs which previously had not changed in three thousand years.
The most famous of these contests was held at the London Exhibition in The London Exhibition occurred at the peak of British industrial power. Because Britain was noted as the "workshop of the world," the English decided that they needed a chance to show their products and technology.
This was an effort to bolster trade and to demonstrate that their varied technology ranked favorably with their foreign competitors. The exhibition was an epic event. Its catalog, running hundreds of pages, described commodities and technologies, with diversity that included steel furnaces, pottery, firearms, and locks.
Locomotives, steam hammers, sewing machines, musical instruments, photographic equipment, and every other significant product and process available was on display. Public confidence in the locks of the day was high, especially as each new improvement was introduced, and the difficulties of defeating these inventions was demonstrated to the public.
The exhibition gave lock makers a chance to offer rewards to anyone who could pick their wares, and thus, they were able to show the security of their devices. Alfred Hobbs was able to bypass the Bramah lock. The high point of the exhibition was the offer of two hundred pounds by the Bramah Company to the person who could successfully open their pickproof lock.
It will be remembered that this lock, originally developed some fifty years before, had remained one of the most secure in the world; nobody had succeeded in manipulating it open. Then Alfred Charles Hobbs arrived from America. Hobbs announced that he could easily pick the most difficult of lever locks, the one made by Bramah. Of course, he was scoffed. But he persisted. The Bramah Company finally set up an impartial panel of judges, gave him a sample of their lock, many blank keys, a place to work, and thirty days in which to crack the invincible device.
While the two hundred pound reward was a great deal of money, the company believed that they had nothing to lose, since no one had been able to break the lock. The "fence" had multiple slots corresponding with the position of each slider.. Hobbs diligently worked at his task. One day he would spend many hours at his workbench, another only minutes. At the end of twenty-four days, he summoned the judges.
With his observers watching, Hobbs confidently took the key he had made, inserted it into the lock, and unlocked the mechanism. The judges were incredulous. The lock makers claimed that it was a trick or that it was just luck. So he relocked the lock, opened it, and again relocked it, all very easily. Nevertheless, said the manufacturer, the mechanism is surely damaged. Not so, Hobbs claimed. To the chagrin of Bramah, the most secure lock of the time had been defeated.
The task was clear: a new, more secure device had to be developed. Both American and English locksmiths took up the challenge. In , the answer came in the form of the Yale pin tumbler, which today is used throughout the world.
Its development revolutionized the lock-making industry as the lever lock had done a hundred years before. It is interesting to note that Hobbs never disclosed to the Bramah Company precisely how he was able to open the lock. The company felt that Hobbs had used some to open the lock, and that the competition was. After a careful examination of the original lock, it is the author's conclusion that Hobbs decoded the slider position in much the same fashion that John Falle constructed his pin and cam system to read minute tolerance variations.
It would have been relatively easy for Hobbs to determine the play between the gate within each slider, and the barrier that formed a fence, and then to construct a key. The Chicago Tubar lock and many other variations of the sidebar mechanism can be viewed as an offshoot of the original Bramah lock.
In the case of the Tubar, the sliders were replaced with two rows of four pins with gates cut into the lateral area of the pin. In the Bramah lock, the "sidebar" is comprised of two fixed rings that block the movement of the sliders. In the Tubar, the sidebars are moveable; however, they perform the same function. See the accompanying video of the interview with Jeremy Bramah. Linus Yale, Sr. He was an ingenious and successful inventor and manufacturer of bank locks.
His son Linus Yale, Jr. First developed by Yale in , the pin tumbler mechanism was refined and presented to the public by Yale, Jr. Between and , Yale, Jr. View all 4 comments. Jan 17, Gregory rated it it was amazing. The big black book of all things related to locks. Absolutely the authority. Hugo rated it it was amazing Nov 27, Colby Moore rated it really liked it Nov 16, Lothario Escobar rated it it was amazing Apr 17, Nick rated it it was amazing Apr 09, Chris Buckley rated it it was amazing Mar 29, Kyle rated it it was amazing Jul 22, Mike rated it it was amazing Apr 07, Steve rated it it was amazing Nov 06, Wolfgang Dirksen rated it really liked it Jan 01, Will rated it it was amazing Nov 01, Martin D Johnson rated it it was amazing Apr 25, Todd added it Jul 15, Dana Lyn Stephenson marked it as to-read Sep 11, Jeff added it Sep 15, Himanshu marked it as to-read Jan 14, David added it Jun 09, John Goen marked it as to-read Feb 14, Ryan marked it as to-read Apr 27, Steve added it Jul 29, Aljoker added it Aug 31, Mohamed Hisham marked it as to-read Sep 01, Sam marked it as to-read Nov 11, Samuel Mello marked it as to-read Nov 22, Arbolsano Es marked it as to-read Nov 28, Aidan marked it as to-read Nov 28, A network license may be obtained from the author.
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