why all cow is flawed
Posted: Sat Dec 01, 2012 2:36 pm
OK Firstly ...It will be said that if one does not like or have valid concerns one needs to submit a rule change form ..... dear readers this will be submitted by the author in conjunction with discussion, as a rule change requires the support of those considering said change and the general support of the affected members ...so through this post I hope to convince DLRA members that the SCTA ( and by proxy DLRA) all leather rule is not only ill considered but possibly dangerous.
To the best of my knowledge the all leather rule came about when one (1) SCTA rider had an incident with an on board fire and received burn injuries I believe they were secondary burns from steam generated underneath the leathers ...im not privy to the details or know if the rider was wearing leathers with stretch panels or perforations ... but from this incident a rule change was made which made it mandatory for the use of "all leather" riding suits...and later some lee way in allowing palm sized stretch at the back of the knees and under arms .
Here I will try to logically and scientifically put forward my personal view why this is a bad rule.
1. The physical properties of leather and how its affected by flame impingement through the process of conduction....I don't want to delve to deeply into the science and maths ( but if you are interested I can provide links) ...Leather is a natural product consisting of the tanned and processed hides of animals ,for most circumstances riding leathers are from a bovine source ie. cows. All substances have a property known as thermal conductivity measured in W/(M.K) the lower the number the greater is its resistance to conducting heat EG metals have a high conductivity rate whereas insulating materials have a low value. Leather has a relatively low value of 0.14 which makes it a good choice for resisting heat conduction BUT this is only under certain circumstances it MUST be dry... the way the fibres of leather are arranged is it allows air to be trapped within its structure, Air is a very good insulator with a value of 0.026 much better than the leather its self.
But leather has another property its hydroscopic ..it absorbs moisture very well ..it wicks up your perspiration and becomes saturated with water displacing the air ...water has a conductivity higher than air 0.59. Also leather holds onto its moisture and takes time to dry out and its also traps salts and acids (more on this later ).
We race in a very hot place... inside our all cow suits we sweat like pigs and very soon our leathers are quite wet ( there is no ventilation) normally this would be of concern only for our ability to keep cool and the possibility of overheating our bodies ( which is why they ventilate them) now we have the situation where we have wet leathers there thermal conductivity is higher and we have a fire on-board while racing down the course do we bail out or ride it out and endure the fire for the time it takes to stop and dismount? ....If we ride it out and depending on the severity of the fire and the time to stop the heat penetrates through the leathers ( not the flames ) and heats up the trapped perspiration which becomes steam and causes burns there by negating the very reason for THE RULE which is supposed to help.
Ok so is there any alternative? And if so is it practical? I believe there is and it involves 3 processes.
Process 1.... alter leathers tendency to be hydroscopic....my research shows that the best way to do this (from leather industry sources) is to treat the leather with a waterproof fatliquor this keeps the leather dry ...but for it to be effective the leather must be free of acids and salts sadly used leathers would have accumulated through sweat salts and acids ...I'm not sure if they could be treated by professional suit leather manufactures ...this may help keep the leather dry but inside it will be a sauna bad for health and the heat will still boil the sweat and cause burns.
Process 2...... wear thermal insulation under the leathers ... contrary to popular belief Nomex is not a good insulator it has a medium thermal conductivity of 0.25 and its primary purpose is to not burn ..in actual fact it would be better to wear it outside of the leather ..... so what else well some natural fibres are good insulators and they have the added benefit of wicking the sweat away from the skin keeping us dry and cooler ( if there is ventilation ) silk, cotton 0.029 wool 0.039 ..there are better synthetic fibres but unlike natural they melt in high heat ... one exception is a fibre called carbon X it is an excellent insulator wicks away sweat and is extremely flame proof .....look it up .... BUT without a way for the moisture to evaporate it stays trapped inside where it can if heated turn to steam SO.
Process 3 Use ventilated leathers this allows the moisture inside to escape and allows cooling dry air inside to help evaporate the moisture .... this will keep the rider cooler and dryer which is the exact opposite to the all leather rule.
As can be deducted from the above data all leather riding suites are not the way to protect us from the incidence of a fire aboard and can be actually harmful in such a case ..as well as creating a potentially harmful sauna condition for riders and giving rise to heat related sickness.
leather properties (some)
• High Tensile Strength.
• Resistance to tear, this is due to the three dimensional fibre weave.
• High resistance to flexural fatigue.
• High resistance to puncture.
• Low bulk density. Because of its fibrous nature the bulk density of leather is low without impairing its other qualities.
• Good heat insulation. As its low bulk density indicates there is a considerable amount of air in the interstices between the fibres of leather. The air clings to the fibre surfaces, being static; the air is a poor conductor of heat, an important factor in bodily comfort.
• Permeability to water vapour. At relative humidity leather fibres will hold more water vapour than any other fibre. This property enables leather to absorb perspiration which is later dissipated.
• Thermostatic properties. Leather is warm in winter and cool in summer.
• Mould ability. Leather can be moulded and will retain its shape.
• Anti-Fungal properties. Leather is treated for resistance to mildew and rot.
• Resistance to fire. Leather resists heat and flame, making it a safety conscious option in the modern abode, for this reason leather is also used in protective clothing.
fatliquors
NERAL: SYNTHOL DS 600 is mostly used as a single fatliquor. SYNTHOL DS 600 is best used alone, without additions. Combinations with other waterproofing fatliquors are possible when a specific handle is required or waterproofing demands are less severe. SYNTHOL DS 600 has a relatively low sensitivity to the presence of electrolytes and acids. For this reason it can be used even under less than ideal circumstances where other waterproofing fatliquors would not be able to give maximum effects. However, the presence of electrolytes should still be avoided as much as possible and good washing after neutralization and possibly before fatliquoring is essential. SYNTHOL DS 600 does not require a high neutralizing pH to be effective. Uniform de-acidification is essential, however, and for best results, an over- night neutralization to a final pH of 4.7-4.8 is recommended.
Gary #282
To the best of my knowledge the all leather rule came about when one (1) SCTA rider had an incident with an on board fire and received burn injuries I believe they were secondary burns from steam generated underneath the leathers ...im not privy to the details or know if the rider was wearing leathers with stretch panels or perforations ... but from this incident a rule change was made which made it mandatory for the use of "all leather" riding suits...and later some lee way in allowing palm sized stretch at the back of the knees and under arms .
Here I will try to logically and scientifically put forward my personal view why this is a bad rule.
1. The physical properties of leather and how its affected by flame impingement through the process of conduction....I don't want to delve to deeply into the science and maths ( but if you are interested I can provide links) ...Leather is a natural product consisting of the tanned and processed hides of animals ,for most circumstances riding leathers are from a bovine source ie. cows. All substances have a property known as thermal conductivity measured in W/(M.K) the lower the number the greater is its resistance to conducting heat EG metals have a high conductivity rate whereas insulating materials have a low value. Leather has a relatively low value of 0.14 which makes it a good choice for resisting heat conduction BUT this is only under certain circumstances it MUST be dry... the way the fibres of leather are arranged is it allows air to be trapped within its structure, Air is a very good insulator with a value of 0.026 much better than the leather its self.
But leather has another property its hydroscopic ..it absorbs moisture very well ..it wicks up your perspiration and becomes saturated with water displacing the air ...water has a conductivity higher than air 0.59. Also leather holds onto its moisture and takes time to dry out and its also traps salts and acids (more on this later ).
We race in a very hot place... inside our all cow suits we sweat like pigs and very soon our leathers are quite wet ( there is no ventilation) normally this would be of concern only for our ability to keep cool and the possibility of overheating our bodies ( which is why they ventilate them) now we have the situation where we have wet leathers there thermal conductivity is higher and we have a fire on-board while racing down the course do we bail out or ride it out and endure the fire for the time it takes to stop and dismount? ....If we ride it out and depending on the severity of the fire and the time to stop the heat penetrates through the leathers ( not the flames ) and heats up the trapped perspiration which becomes steam and causes burns there by negating the very reason for THE RULE which is supposed to help.
Ok so is there any alternative? And if so is it practical? I believe there is and it involves 3 processes.
Process 1.... alter leathers tendency to be hydroscopic....my research shows that the best way to do this (from leather industry sources) is to treat the leather with a waterproof fatliquor this keeps the leather dry ...but for it to be effective the leather must be free of acids and salts sadly used leathers would have accumulated through sweat salts and acids ...I'm not sure if they could be treated by professional suit leather manufactures ...this may help keep the leather dry but inside it will be a sauna bad for health and the heat will still boil the sweat and cause burns.
Process 2...... wear thermal insulation under the leathers ... contrary to popular belief Nomex is not a good insulator it has a medium thermal conductivity of 0.25 and its primary purpose is to not burn ..in actual fact it would be better to wear it outside of the leather ..... so what else well some natural fibres are good insulators and they have the added benefit of wicking the sweat away from the skin keeping us dry and cooler ( if there is ventilation ) silk, cotton 0.029 wool 0.039 ..there are better synthetic fibres but unlike natural they melt in high heat ... one exception is a fibre called carbon X it is an excellent insulator wicks away sweat and is extremely flame proof .....look it up .... BUT without a way for the moisture to evaporate it stays trapped inside where it can if heated turn to steam SO.
Process 3 Use ventilated leathers this allows the moisture inside to escape and allows cooling dry air inside to help evaporate the moisture .... this will keep the rider cooler and dryer which is the exact opposite to the all leather rule.
As can be deducted from the above data all leather riding suites are not the way to protect us from the incidence of a fire aboard and can be actually harmful in such a case ..as well as creating a potentially harmful sauna condition for riders and giving rise to heat related sickness.
leather properties (some)
• High Tensile Strength.
• Resistance to tear, this is due to the three dimensional fibre weave.
• High resistance to flexural fatigue.
• High resistance to puncture.
• Low bulk density. Because of its fibrous nature the bulk density of leather is low without impairing its other qualities.
• Good heat insulation. As its low bulk density indicates there is a considerable amount of air in the interstices between the fibres of leather. The air clings to the fibre surfaces, being static; the air is a poor conductor of heat, an important factor in bodily comfort.
• Permeability to water vapour. At relative humidity leather fibres will hold more water vapour than any other fibre. This property enables leather to absorb perspiration which is later dissipated.
• Thermostatic properties. Leather is warm in winter and cool in summer.
• Mould ability. Leather can be moulded and will retain its shape.
• Anti-Fungal properties. Leather is treated for resistance to mildew and rot.
• Resistance to fire. Leather resists heat and flame, making it a safety conscious option in the modern abode, for this reason leather is also used in protective clothing.
fatliquors
NERAL: SYNTHOL DS 600 is mostly used as a single fatliquor. SYNTHOL DS 600 is best used alone, without additions. Combinations with other waterproofing fatliquors are possible when a specific handle is required or waterproofing demands are less severe. SYNTHOL DS 600 has a relatively low sensitivity to the presence of electrolytes and acids. For this reason it can be used even under less than ideal circumstances where other waterproofing fatliquors would not be able to give maximum effects. However, the presence of electrolytes should still be avoided as much as possible and good washing after neutralization and possibly before fatliquoring is essential. SYNTHOL DS 600 does not require a high neutralizing pH to be effective. Uniform de-acidification is essential, however, and for best results, an over- night neutralization to a final pH of 4.7-4.8 is recommended.
Gary #282