Anyone here been a cycle courier?

[anglo-saxon]

One day, buried somewhere in the News of the World, there will be a picture of a rather delicate-looking young fellow. The brief story will tell how his constitution was not up to the task of the rigours of military basic training, how he felt lonely and isolated after receiving a nasty paper cut and then fractured an eyelash during ablutions, and how he felt ultimately bullied by "the big meanies". It will not tell of his mealy-mouthed back-chat, of his irritating tendency to over-analyse the simplest of instructions to the annoyance of his superiors and peers, or of his capacity to bore grass with his philosophical drivel and reminiscences of choir practice and music lessons. But finally, it will describe his teary reunion with his mum at the camp gates as she leads him gently away by his slender, lily-white fingers, back to a quiet existence of piano, parcel delivery, and Horlicks.

The poor wee snapper. If only he had been given some chores and the odd slap to the head as a rug rat, instead of fiddling about under the choir master's cassock all those years, he might have made something of himself.

Tish, tish!

A-S, out!

[Pilgrim Norway]

Ah, wait, I see another Bus Stop …… I shall alight.

It would seem that Sarastro is possibly in to something here….

This unique career hop could indeed be excellent training
for him to become a DR…….

After all :-
He would only need Basic Training and the Commando Course first.

Now then – I was a DR….. It is indeed a fun and exciting job…..
Riding your little 1937 BSA sidevalve 350 through deserts and jungles.

With several costume shifts during the monsoon season in order to be
quite dry when you finally present your Despatches to a grateful officer.

DR’s earned the respect and admiration of all colleagues in the Corps…..

DR’s always seemed to be out on a job when needed by their allies….
Or off “fixing the bike” –

I wish that I had had the prior experience of being a cycle courier before
embarking on my career as a DR – which was enlivened by ripping gaily
down the Bukit Tima Road to deliver “something” and flying back up
to Sembawang with “Something else” Oh, the freedom of flying hither
and thither on wheels of wire and rubber….. Not a care in the world….

I don’t seem to remember the mascara though – and we usually wore
shorts and not tights – still -

[Sarastro]

Sounds like a damn sight more fun through deserts and jungles than through fat yuppies in fast cars around London, Pilgrim. If it was a 1937 bike, when were you doing this?

A-S, nice to see you took the high road, I shall look out for that picture next to your four-letter single-word obituary.

[Wholley]

PS On most of the lists of most dangerous professions in the world that I've seen, pretty much top comes truck drivers, long-haul delivery drivers, motorcycle delivery types.
If they wear stab proof armor how are there so many stab injuries.

.

Iv'e done both and my wife still doe's one.
I do the other one now.
Your"Stab Proof Vests"Are in fact Ballistic Level 11A's.
They are designed to stop a round,Not a knife..
For British Police ask Black Rat but I'm pretty sure you'll get the same answer.There's a trade off between protection and the ability to get out of your car and chase a miscreant.
For a vest to be both ballistic and stab proof it would have to weigh almost twice as much and would be way to bulky.
Having said that we here have a height and weight requirement.
Plus we have to get through POPAT every two years.
On top of that we have Firearms qualification every six months.
Side arm ,Back-up and shotgun.More if your Rifle qualified..
Wears me out just thinking about it.

Now Who said summat about Fat Copper's?

[hc00]

PS On most of the lists of most dangerous professions in the world that I've seen, pretty much top comes truck drivers, long-haul delivery drivers, motorcycle delivery types.
If they wear stab proof armor how are there so many stab injuries.

.

Iv'e done both and my wife still doe's one.
I do the other one now.
Your"Stab Proof Vests"Are in fact Ballistic Level 11A's.
They are designed to stop a round,Not a knife..
For British Police ask Black Rat but I'm pretty sure you'll get the same answer.There's a trade off between protection and the ability to get out of your car and chase a miscreant.
For a vest to be both ballistic and stab proof it would have to weigh almost twice as much and would be way to bulky.
Having said that we here have a height and weight requirement.
Plus we have to get through POPAT every two years.
On top of that we have Firearms qualification every six months.
Side arm ,Back-up and shotgun.More if your Rifle qualified..
Wears me out just thinking about it.

Now Who said summat about Fat Copper's?

Like I said most of the police in my area are fat.

They were described to me as stab proof vests by the policemans son. So I assumed he was correct.

I would have thought if it can stop a bulet it could stop a knife, I know theres more energy behind the knife but the knife will be moving alot slower.

You learn something new every day.

[Wholley]

Hc00.
The science here is real simple.
Most handgun rounds are designed to spread or fragment on impact.
The trauma plate in most ballistic vests can easily deal with the expansion.
A knife however does not expand obviously.
FMJ rounds at rifle velocities will also easily defeat a ballistic vest.
I hear the collared versions of the level 2 have caused neck injuries among British police while exiting their cars at a rate of knots.
On this side of the pond we don't see many stab wounds to Officers.
The old adage"Don't bring a knife to a gun fight"Applies
If you wave a knife at me I'll shoot you.
As to rifle rounds,If one hits me I'll probably know nothing about it.

[Sarastro]

Also HC, various types of material used in bulletproof vests are actually quite soft, but harden on impact (there's a physics / chemistry term for this, but I can't remember it viscosity, possibly?); essentially the material transfers the energy of the moving object which strikes it at one point and dissipates said energy over the entire vest, this transferance makes the vest temporarily go rigid. Thus it is actually easier to get a knife through this material (less energy in your average person stabbing a knife than a speeding bullet); in fact, strangely enough the slower you strike with the knife, the easier it will be to get through. There are many different types of bulletproof vests though (body armour worn by soldiers is essentially a metal plate, I think?), and I doubt any made entirely of such materials, so it isn't quite that simple, but interesting science all the same. Plenty of other materials have these properties, silly putty for example, because it has a certain kind of elasticity, is easy to mould slowly, but if you bounce it off walls will remain hard and in shape.

Currently the car industry is doing a lot of research into using liquids and foams which do the same thing (under certain circumstances, ie within a certain structure or under a magnetic field), which is quite impressive; think of shaving foam which if you hit it turned into polystyrene.

[hc00]

Also HC, various types of material used in bulletproof vests are actually quite soft, but harden on impact (there's a physics / chemistry term for this, but I can't remember it viscosity, possibly?); essentially the material transfers the energy of the moving object which strikes it at one point and dissipates said energy over the entire vest, this transferance makes the vest temporarily go rigid. Thus it is actually easier to get a knife through this material (less energy in your average person stabbing a knife than a speeding bullet); in fact, strangely enough the slower you strike with the knife, the easier it will be to get through. There are many different types of bulletproof vests though (body armour worn by soldiers is essentially a metal plate, I think?), and I doubt any made entirely of such materials, so it isn't quite that simple, but interesting science all the same. Plenty of other materials have these properties, silly putty for example, because it has a certain kind of elasticity, is easy to mould slowly, but if you bounce it off walls will remain hard and in shape.

Currently the car industry is doing a lot of research into using liquids and foams which do the same thing (under certain circumstances, ie within a certain structure or under a magnetic field), which is quite impressive; think of shaving foam which if you hit it turned into polystyrene.

Both these posts have been learning experiences.

Things which are soft but hard when hit at higher velocities I have heard being called anti neutonian substances. Not sure if thats the right name or not but thats what ive heard them reffered to as.

And a knife stabbing has alot more energy than a bullet believe it or not.

A bullet travels at huge speeds but doesn't wiegh much.

A knife (I used a fist in the first time I explained this to someone but a knife fits too) moves 100's of times slower but has alot more wieght than a bullet.

And force (energy) is wieght/mass times speed/velocity (these while not being the same thing are interchangable at this simple level)

.223 = 55 grains x 3200 fps (American bullet out of an M16) = 176000

Knife wieghing 500g being stabbed at a slow speed.

7716 grains (500 grams) x 44 feet per second (30 mph) = 339504

Bullet = 176000
Knife = 339504

And that isn't accounting for the added wieght of the fist holding the knife and the arms force and such. the knife would actually have more energy in the real situation than in this example.

Sorry for going on about it but most people ive explained this funy fact to (a proper punch has more energy than most bullets, or a stab in this example) dont believe me and need me to go into this level or depth for them to understand.

E.g. Did you know a proper punch thrown from the hip and not the shoulder has much more force than a .50BMG from an M82A1?

[Sarastro]

Kickass, you clearly know all about this then

I can see the knife example, though I suspect you've missed out the effect surface area has: ie only the tip of a knife has a small surface area, so while that may penetrate the vest, it isn't going to go very far as an ever increasing surface area of the knife has to penetrate the vest while the velocity is decreasing, acting as a brake. An ice-pick, for example, being essentially a long thin spike, would be much more effective than a knife at the same force as it retains roughly the same surface area. Bullets are similar (though armour piercing rounds are designed, I think, with this principle in mind, in that they don't flatten or fracture on impact like most rounds, thus the surface area stays the same).

Same thing for a properly thrown punch, while it may have more energy than a round from a BMG (which I didn't know...is this a Bruce Lee punch? ), it also has hundreds of times the surface area, so the energy is hugely dissipated.

Then again, it's been a while since I did any real science, so I may be missing something obvious here...any ballistics experts around?

[hc00]

Kickass, you clearly know all about this then

I can see the knife example, though I suspect you've missed out the effect surface area has: ie only the tip of a knife has a small surface area, so while that may penetrate the vest, it isn't going to go very far as an ever increasing surface area of the knife has to penetrate the vest while the velocity is decreasing, acting as a brake. An ice-pick, for example, being essentially a long thin spike, would be much more effective than a knife at the same force as it retains roughly the same surface area. Bullets are similar (though armour piercing rounds are designed, I think, with this principle in mind, in that they don't flatten or fracture on impact like most rounds, thus the surface area stays the same).

Same thing for a properly thrown punch, while it may have more energy than a round from a BMG (which I didn't know...is this a Bruce Lee punch? ), it also has hundreds of times the surface area, so the energy is hugely dissipated.

Then again, it's been a while since I did any real science, so I may be missing something obvious here...any ballistics experts around?

The surface area is the main limiter to them yes. i just always thought bullet proof = knife proof lol

[Doc]

So HC what your saying is you'd prefer to be shot than punched

In the kinnetics of injury, velocity is more important than mass.

Kinnetics of injury between a knife stab and being shot are totally different and cant just be debated on mass over velocity.

The whole idea of body armour is protection. If someones punching you, you have other means of protection such as self defence, also with a knife attack. But if you have a sniper half a mile away firing a .50cal round at your left nipple, prancing around jap slapping into thin air is not going to do you much good. Hence body armour. Body armour is also designed to contain an injury and maintain body structure after for example a blast injury.

[hc00]

So HC what your saying is you'd prefer to be shot than punched

Shot by a bb gun yes, but otherwise no lol

In the kinnetics of injury, velocity is more important than mass.

Kinnetics of injury between a knife stab and being shot are totally different and cant just be debated on mass over velocity.

The whole idea of body armour is protection. If someones punching you, you have other means of protection such as self defence, also with a knife attack. But if you have a sniper half a mile away firing a .50cal round at your left nipple, prancing around jap slapping into thin air is not going to do you much good. Hence body armour. Body armour is also designed to contain an injury and maintain body structure after for example a blast injury.

No I know velocity and small surface area are important in injury. i was just stating that bullets actually have less energy than you'd expect.

[Doc]

I do agree with you bud just pointing out theres alot more to it.

[Hostage_Negotiator]

My current issue vest offers KR2 (Knife Resistant) and HG2 (Hand Gun) level protection is collarless and weighs around 6lbs. Best bit of kit I've ever been issued!