Information
How Bowls Are Made
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Modern Methods First Phenolic powder has to be produced. All manufacturers use powders with different specific gravities to achieve their desired weights for the various models. The powder manufacturer has to design the powders to suit the moulder's requirements of flow characteristics, colour, surface finish, etc. After the ingredients are blended, the initial process to produce the powder can commence which involves both heat and pressure. The chemical bonding process begins at this point, and the resulting "cake" is ground to the powder size specified by the moulders. Checking that the specific gravity is correct is a regular feature throughout the production and can be altered to ensure conformity to the requirements of the customer. Next is the moulding of the blank. It is believed that the moulding "blank" for a bowl is the largest solid mass of Phenol compound moulded successfully. Before the powder is placed into the mould it is passed through a radio frequency preheater which ensures that the moisture is removed and that the "cake" is heated right through. This also restarts the chemical bonding process and thus helps reduce the time required in the mould. After the pre heating is completed the "cake" is put into a computer-controlled 160 tonne compression moulding press, the platens of which, are heated to 200°C. The "cake", which is then pressed into the final shape, remains in the press for 5.5 minutes and then merges as a blank which we can use in our computer-controlled lathes. The blanks are then left to cool under controlled conditions so that the full cure can be successfully completed. Then they are sonic-checked for voids before being ready for use. |
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STAGE 1 Composition blanks are carefully inspected and electronically weighed, the first of many inspections which are carried out during the course of production. |
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STAGE 2 The material is so hard and abrasive the blanks are turned using diamond tools. Consistency of shape and performance is ensured by the use of computer controlled machinery. |
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STAGE 3 Continuing with the accuracy of shape and size other C.N.C. equipment is used at the secondary operations. Further weight checks to confirm compliance with W.B.B. (World Bowls Board) requirements are also carried out. |
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STAGE 4 Computers are also used to engrave the sets of 4 bowls. At this point the set has its unique set number, serial number and the W.B.B. & manufacturer's identification engraved on it. |
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STAGE 5 After engraving, painting of the print and emblems is carried out to enhance the appearance of the bowls. This also aids identification when in play. |
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STAGE 6 Final testing using the approved and licensed test table. All bowls are tested to the W.B.B. "Master" bowl. As well as having to comply with the even more rigorous requirements of the manufacturers. Thus the different models are tested to their model specifications to confirm that their performance will be optimal for given greens. |
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Traditional Methods The tradition of making bowls in Liverpool goes back a long way. Sometime after 1409, we do not know the actual date, bowls of wood were used, made from boxwood, holly, yew or oak. It is presumed that lignum vitae was introduced in making bowls during the 16th century. Lignum vitae is a timber now on the United Nation CITES list, which means it requires special licences for export and import. The way lignum vitae bowls were made was a skilled job, not just from the turning, but right through from the selection of the original logs. There are three species of lignum vitae and only one is really suitable. That is "Guiacum Officinale", so knowledge of the species is required. Interestingly, lignum is bought by weight, rather than more usual for logs, cubic measurement. Once the logs were accepted as the correct species, the next stage in the selection can proceed. Those logs which had too large a heart crack, would be unsuitable, note however that all lignum vitae has a heart crack and it is probable that the white mounts (discs) were used to hide these cracks. The heart of the timber has also to be positioned in the log to allow it to be the centre of the bowl, so if it was too close to one side to allow for this, the log would be rejected. The timber itself is very dark in colour, but the sap wood is pale yellow in colour and is sharply defined; it is only the dark timber that is required, so any logs that did not have sufficient diameter of dark timber would be rejected, and, equally, if the log was too large in diameter, resulting in too much waste, this would also be rejected. So, after the initial careful inspection and selection, the timber selected would be purchased. The next stage is to produce the "blanks" from which the craftsman turner, would make the bowls. For any bowls, to make a set, the "blanks" have to come from the same log, and from side-by-side in that log, otherwise the specific gravity of the bowls would not be the same and the likelihood of the bowls being of "similar" weights could not be expected, or achieved. The first stage of producing the "blank", or timber, was basically to produce a cylinder which could be put between the centres of a ball-turning lathe. It is worth noting that at every stage, the timber requires careful inspection and sealing, to ensure it has not cracked. The craftsman turner, would take the rough ball-shaped blank, and turn it into the shape of a bowl. The skill required to do this, using only hand tools and a template to give the running sole shape was, to say the least, an art, and was all down to eye and hand co-ordination as well as experience. By offering up the sole template to the piece being turned, and judging the amounts of material to be turned off, the craftsman would produce the required shape and dimensions. They would also position the top rings which delineated the running sole. After the mounts (discs) would be fitted and the inner rings and any other decoration would be cut on to the bowl. Then followed the next most skillful job, checking out the bias. As you can imagine, even allowing for the skill of the turner, the bowls required biassing to that specified by the customer and governing bodies of the game. The examination of the bias was, and still is, done on the test table, which is used as a quality control device rather than the means of knowing what the bowl would do on the green. It is amazing just how little material needs to be sanded off to adjust the bias of a bowl either to make the bias stronger or weaker. The skill is knowing how to remove as little as possible, while still being able to retain the basic geometric "proven template" shape. If the "proven template" shape is altered, then the bowls may be able to be made to run down the test table acceptably, but might not do so on the green; thus great skill and knowledge is required. Finally, the bowl would have been hand-polished, either black if the original timber was not considered to be 100%, or natural if the timber was considered the very best. I am sure there are still a lot of crown green bowlers who have fond memories of the "Extra Quality" bowls, which were polished natural and had the Deluxe decoration on them. I know that if any bowler has lost their bowls, they always seem to describe them as being of that quality! Now we use a very hard-wearing spray finish rather than hand-polishing. These traditional skills still exist, although now the "ball" shape blank is turned on the same C.N.C. lathes as they use for composite bowls. Composition bowls are more accurately made to the required geometric shape than could have been achieved by even the most skilled craftsman. All the other skills remain the same, especially, when it comes to the biassing. The new lignum vitae bowls will lose some 20g - 46g in weight in the first year, after that, with care and attention, involving bowls being repolished at least bi-annually, they should give many, many years of service. One of the reasons that composition bowls were first introduced; Dunlop company being one of the first to use a rubber compound, found that in hot weather, especially in the Southern hemisphere, lignum vitae bowls were prone to split. So, in Australia and New Zealand, bowlers would probably only know lignum vitae bowls from their display cabinets, whereas in the North of England we see many thousands of crown green lignum vitae bowls still being used. So, "woods" are still going strong, but the Composition bowls are taking a larger and larger market share. - Peter N. Clare - Director of Drakes Pride |
It is now even more difficult to obtain suitable timber for the manufacture of bowls. Lignum vitae is one of the most outstanding of all timbers, it is not only one of the hardest and heaviest known, but has an almost unique property of being self-lubricating. As a result, not only was it used for lawn bowls, but also for bearings and bushing blocks for propeller shafts of ships, as well as pulley sheaths. Those who had high-quality mangles to put the washing through, would also perhaps have recognised that the bottom roller was sometimes made from lignum vitae.Bowls History
No one ever speaks about the history of bowls without referring to Sir Francis Drake, playing at Plymouth on 19th July 1588, when Captain Thomas Flemming advised that the invading Spanish Armada had been sighted off the Lizard. His response has gone down as one of the most famous lines in history: "There is plenty of time to win the game and thrash the Spaniards too". However, almost 300 years earlier, the Southampton Bowls Club green is reputed to have been laid and in regular use since 1299. Chesterfield Bowling Club claims their rink dates from 1294 and, certainly in the early part of the 14th century, Edward III banned the playing of bowls so that the 'Bowman of England' would practice their archery. It does seem that bowls has not always been associated with the gentle art as we now know it, and during its early years the game was prohibited and quite high penalties could be levied by magistrates, if anyone broke the prohibition.
There is no real evidence as to the style of game, although during the reign of Richard II, bowls was then referred to as "gettre de pere" presumably Norman French for "jetter de pierre" and so obviously describes throwing a "stone". So there is not much doubt that the original bowls were made from stone. They would be as round as possible, nothing like the shape we now use. Sometime after 1409, we do not know the actual date, bowls of wood were used, made from Boxwood, Holly, Yew or Oak. It is presumed that Lignum Vitae was introduced in making of bowls during the 16th century, after the discovery of the Santo Domingo in 1492. Santo Domingo is in the Caribbean Sea, where the best Lignum Vitae is sourced, which is still true to-day.
According to anecdotal evidence, the introduction of bias to the design of bowls seems to have been by accident. It is said that in 1522, Charles Brandon, Duke of Suffolk, whose bowl split in two on striking another bowl, rushed into the house and took off the spherical knob from the banister post to provide himself with a replacement bowl. The flat cut then caused his substitute bowl to roll with a bias. Observing this effect, the Duke experimented by curving his bowl around others. He passed on his knowledge to his friends, and so, in the course of time, biased bowls came into general use.
Later, bias was produced by loading the bowls on one side by inserting weights, and some players think that this is still done today; so it is that even now we occasionally find bowls, which have been brought in for renovation or re-adjusting, to have been loaded by inserting metal or lead on one side of the bowl.
To bias by loading in this manner is no longer permitted by the rules and the bias is now produced entirely by the shape of the bowl. In fact with the bowls made to todays very tight specifications such loading would cause the bowls to perform erratically, a similar problem to a car wheel that is out of balance. Further information about bias will be covered in other articles.
Prior to 1871, the bias of bowl was not stipulated and a test of any kind was unknown. The bowls were entirely hand-turned and finished in the absence of any testing method. It was impossible for bowls turners to make bowls which could be accurately matched. Every bowl was different and indeed matching bowls were not expected by the players.
In 1871, Taylors of Glasgow constructed the first testing table. The idea was to allow the company to produce matched bowls from the factory rather than waiting for the customers vague comments as to their requirements.
A test table allowed the production of bowls that perform on the test table (note the wording "on the test table") in a given manner and Taylors specified these as number I through to number 5 bias, number I bias being the weakest and number 5 the strongest. When the Scottish bowls association carried out their testing, they were then able to agree and thus adopt in 1893 the number 3 biased bowl as their standard.
There are many bowlers who will remember the reference to number 3 bias, which was still regularly mentioned up to a few years ago. Crown green bowlers will also note that their standard was selected using the same five biases and that the number 2 was considered not strong enough, but number 3 bias was too strong. Thus, 2 full or slightly stronger than 2 bias was selected. It is uncertain as to the date when the crown green bias was first selected.
Most modern test tables are based on using standard billiards/snooker tables, because of their rigidity of construction and the accuracy of level that the slate bed can achieve. In the Hensel booklet "The romance of a bowls manufacture" it mentions the fact that W.D. Hensel tested bowls originally on a standard (l2ft) billiards table, but in 1908 developed the 36ft table. This basically would be achieved using three full-size billiards tables.
In 1928, the I.B.B. (International Bowls Board, now the W.B.B. World Bowls Board) laid down the basis for table testing. The specifications, with a few amendments, are basically still true today. For example, the bowls should still run approximately 28 feet, the maximum draw shall be approximately 4'6". However, one important addition to the specifications is that the running time should be between 12 - 15 seconds. - Peter N. Clare - Director of Drakes Pride
What Are Bowls
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Lawn bowls today are made from a hard plastic called Phenolformaldehyde, they are perfectly round one way (fig. 1) and oval shaped the other (fig. 2). The bias is produced by making the bowl lopsided (fig. 3), however it is so minute that it can't been seen with the naked eye. When the bowl is delivered along its running surface, there is sufficient momentum to keep it running straight along its course. As the bowl slows down it attempts to find its true centre of balance, forcing it to curve. The running surface of the bowl is the part of the bowl which is in contact with the green when in motion. Lawn bowl sizes range from size 00 through to size 7. Only 1 to 2 millimetres in diametre seperates the sizes of bowls, the differences are small but considerable when gripping various sized bowls.
The shape of the bowl varies among brands and models. The visible differences are small, but play a large role in the behaviour of the bowl |
Every bowl has an emblem engraved on each side. One side has a small emblem with the bowl's size, weight, serial number & the manufacturer's stamp around it. The other side has the same emblem, but larger. The small side is the bias side. This means it is the side that it will turn towards when in motion.Bowls Testing
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The main reason to have your bowls tested is due to wear and tear. Wear on a bowl will put a flat on the running sole of a bowl, so while spinning the bowl will have a tendency to run on this flat, negating the bias. The time frame in which you should have your bowls tested will depend on how often you play, the surface you play on and the position you play. The affects that cause wear and tear
The testing of bowls |
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A test table consists of 3 full size billiard tables 9.5 metres long with a slate thickness of 35mm. Testing only takes place when the temperature of the table and the room is within the range of 15°c - 30°c. A chute at one end delivers the bowls smoothly to the table at a maximum angle of 7°, thus a constant speed. The World Bowls Board (WBB) supplies a master or Working Reference Bowl (WRB) which has the minimum amount of bias allowed. Each set of bowls submitted for testing is first cleaned, removing old polish so as not to hinder the run of the bowl and contaminate the running surface. The bowls are then run down the table at a distance of 9 metres, as measured along the chute/jack line, against the WRB, each bowl must have as much or more bias than the WRB in order for them to pass. Each set must also finish within a specified radius for it to be classed as a matched set of bowls. If the set does not comply, the bias on the offending bowl(s) will be altered on a lathe to comply. They are then stamped with an official WBB date stamp and issued with a WBB test report. |
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