Bikes beat skates in law enforcement



M

Mark McNeill

Guest
From The Register -

http://tinyurl.com/ojkf6

Rollerskating coppers defeated by turf
Think 'Daleks and stairs'...


A top-notch UK crimebusting initiative - which saw London's Royal Parks
Constabulary issued with in-line rollerskates - has ground to a halt
after crims realised they could escape simply by scarpering across
grass, the Telegraph reports.

<snip>

Supt Derek Pollock, of London's Royal Parks operational command unit
admitted: "It just didn't work. The moment people realised they were
being chased they would switch to a soft surface.

"If the criminal went on to the grass, the officer giving chase had to
stop, take off his skates then follow him without proper footwear while
carrying his skates."

Pollock, whose officers have returned to their traditional perp-hunting
bikes, further confessed: "Not an awful lot of officers were interested
because it hurts when you fall over."

--
Mark, UK
"'Michael Gilhaney,' said the Sergeant, 'is an example of a man that is
nearly banjaxed from the principle of the Atomic Theory. Would it
astonish you to hear that he is nearly half a bicycle?'"
 
E

elyob

Guest
"Mark McNeill" <[email protected]> wrote in message
news:[email protected]
>
> A top-notch UK crimebusting initiative - which saw London's Royal Parks
> Constabulary issued with in-line rollerskates - has ground to a halt
> after crims realised they could escape simply by scarpering across
> grass, the Telegraph reports.
>

So, there is no backup for skating cops? They are unable to skate around the
area? They are expected to police Hyde or Richmond Park on skates? Not
exactly where the crime is, is it?

Nothing to do with the fact that our streets are too shite to skate on then?
They could just skate around the park .. unless they are put in
inappropriate places?

I'd tend to agree that skates aren't particularly good at catching crooks,
but neither are horses. I know a mounted copper who just loves his job ...
"I don't get to meet all the ****s, the rest do".

Skating in London is hard work. Cycling police and medics is a good thing as
they can carry a fair amount of equipment. Skating is a whole different
ball game. Try fixing the roads before expecting something like this to
work.
 
S

Simon Brooke

Guest
in message <[email protected]>, elyob
('[email protected]') wrote:

> Nothing to do with the fact that our streets are too shite to skate on
> then? They could just skate around the park .. unless they are put in
> inappropriate places?


This takes us straight back to land rovers and green lanes. The streets
of London are not engineered to a lower standard than the surfaced walks
in the park. On the contrary, they're engineered to a much higher
standard. But the walks are smooth enough to skate on and the streets
are not. Why is this? Because damage to the road scales with the fourth
power of axle weight.

The park paths are in good condition because they have very few heavy
vehicle movements. Consequently they don't get worn out.

As a quick comparison of what this actually means, the axle weight of a
bicycle is 60Kg (say, average). The axle weight of a landrover,
1200Kg[1]. A fairly simple calculation shows that it takes 160,000
bicycle journeys to do as much damage to the road/path/lane as one
single landrover journey.

Or put it differently, if green laners are pleading that they 'earn'
their right to use the lanes by doing conservation work, then for each
hour of conservation work the average mountain biker does, the green
laner must do 50 thousand hours[2] or slightly over 5 years (continuous,
without stopping to sleep or eat).

[1] Maximum front axle weight of a Defender 110; the maximum rear axle
weight is 1850Kg but it's unfair to assume that every vehicle is loaded
to its maximum and in practice landrovers used for green laning have
nothing but lardarses in the back.
[2] Assuming on average three lardarses per land rover.

--
[email protected] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; L'etat c'est moi -- Louis XVI
;; I... we... the Government -- Tony Blair
 
E

elyob

Guest
"Simon Brooke" <[email protected]> wrote in message
news:[email protected]
> in message <[email protected]>, elyob
> ('[email protected]') wrote:
>
>> Nothing to do with the fact that our streets are too shite to skate on
>> then? They could just skate around the park .. unless they are put in
>> inappropriate places?

>
> This takes us straight back to land rovers and green lanes. The streets
> of London are not engineered to a lower standard than the surfaced walks
> in the park. On the contrary, they're engineered to a much higher
> standard. But the walks are smooth enough to skate on and the streets
> are not. Why is this? Because damage to the road scales with the fourth
> power of axle weight.


Wasn't anything to do with the point I was trying to make. Our streets are
too shite to skate on compared to, say, France and a lot of Europe. Their
roads are a lot smoother. The park reference was about skating "around the
park " (i.e. grass) rather than taking their shoes off and then running
after someone.

Have no idea what your bone is about.
 
M

Matt B

Guest
Simon Brooke wrote:
>
> This takes us straight back to land rovers and green lanes. The streets
> of London are not engineered to a lower standard than the surfaced walks
> in the park. On the contrary, they're engineered to a much higher
> standard. But the walks are smooth enough to skate on and the streets
> are not. Why is this? Because damage to the road scales with the fourth
> power of axle weight.


Isn't it influenced by footprint size, thus affecting the pressure
applied? A slim woman does more damage to a wooden floor in stilettos
that a fat bloke does in carpet slippers.

> As a quick comparison of what this actually means, the axle weight of a
> bicycle is 60Kg (say, average). The axle weight of a landrover,
> 1200Kg[1].


A bike footprint is what, about 15cm^2? A Landrover, about 300cm^2? If
those guesses are anywhere near the actuality the pressure applied by a
bike is 60kg/15cm^2 and by a Landrover 600kg/300cm^2 or 4kg/cm^2 for the
bike and 2kg/cm^2 for the Landrover. I know which I'd rather have drive
across my lawn ;-)

--
Matt B
 
D

Daniel Barlow

Guest
Mark McNeill <[email protected]> writes:

> A top-notch UK crimebusting initiative - which saw London's Royal Parks
> Constabulary issued with in-line rollerskates - has ground to a halt
> after crims realised they could escape simply by scarpering across
> grass, the Telegraph reports.


I don't know which was the first of the current flurry of news outlets
to report this, but I'm very surprised to hear that it's news.
Indeed, the BBC report
(http://news.bbc.co.uk/1/hi/england/london/4854036.stm) also says "The
Metropolitan Police and the Royal Parks Constabulary are expected to
merge formally within weeks" which is, uh, curious as according to the
Royal Parks site (http://www.royalparks.gov.uk/about/police.cfm), the
Met took over Parks policing almost two years ago.

Given that the officers were issued with skates that had removeable
frames, I think the "grass" excuse is a little lame - it would have
taken very little time for them to unclip and give chase on foot.
Most of the police I see in the Parks these days are driving up and
down the Serpentine Road, and I assume they would also be expected to
stop and get out of the car if the pursued decided to take to the
grass ...


-dan

--
http://coruskate.blogspot.com/ # why skate when you can talk about it instead?
 
A

Anthony Jones

Guest
Matt B wrote:
>> This takes us straight back to land rovers and green lanes. The streets
>> of London are not engineered to a lower standard than the surfaced walks
>> in the park. On the contrary, they're engineered to a much higher
>> standard. But the walks are smooth enough to skate on and the streets
>> are not. Why is this? Because damage to the road scales with the fourth
>> power of axle weight.

>
> Isn't it influenced by footprint size, thus affecting the pressure
> applied?


Do you have any evidence to suggest that it is, other than extrapolation
from wooden floors? The '4th power' rule Simon referenced comes from a
real world test:

http://en.wikipedia.org/wiki/AASHO_Road_Test

The article admits: "Extrapolating the data to different situations has
been 'problematic'", so if you know of a more suitable test, I'm sure
we'd all be interested to hear of it.

> A bike footprint is what, about 15cm^2? A Landrover, about 300cm^2? If
> those guesses are anywhere near the actuality the pressure applied by a
> bike is 60kg/15cm^2 and by a Landrover 600kg/300cm^2 or 4kg/cm^2 for the
> bike and 2kg/cm^2 for the Landrover. I know which I'd rather have drive
> across my lawn ;-)


Your vague arm waving calculation is unnecessary, just look at the
respective tyre pressures. A MTB will typically use around 30psi. I
suspect this isn't massively different from that a Landrover would use.

Anthony
 
C

congokid

Guest
In article <[email protected]>, Daniel
Barlow <[email protected]> writes

>Most of the police I see in the Parks these days are driving up and
>down the Serpentine Road, and I assume they would also be expected to
>stop and get out of the car if the pursued decided to take to the
>grass ...


Alternatively they could crash spectacularly at high speed through the
railings and fences separating the road from the grassy bits.

--
congokid
Eating out in London? Read my tips...
http://congokid.com
 
P

Paulmouk

Guest
"Matt B" <[email protected]> wrote in message
news:[email protected]
> Simon Brooke wrote:
>>
>> This takes us straight back to land rovers and green lanes. The streets
>> of London are not engineered to a lower standard than the surfaced walks
>> in the park. On the contrary, they're engineered to a much higher
>> standard. But the walks are smooth enough to skate on and the streets
>> are not. Why is this? Because damage to the road scales with the fourth
>> power of axle weight.

>
> Isn't it influenced by footprint size, thus affecting the pressure
> applied? A slim woman does more

....
....

> Matt B


Road strength/thickness/material is based on the forecast no. of million
standard lorry axles per year.
Motorways , distributor roads, residential roads, park roads, pedestrian
paths etc etc are not all designed and built to be the same strength.

Paul.
 
T

Tony Raven

Guest
elyob wrote:
>
> So, there is no backup for skating cops? They are unable to skate around the
> area? They are expected to police Hyde or Richmond Park on skates? Not
> exactly where the crime is, is it?
>


But since they are the Royal Parks Constabulary they are restricted to
Royal Parks policing. Outside the Parks the responsibility rests with
the regular police.

--
Tony

"The best way I know of to win an argument is to start by being in the
right."
- Lord Hailsham
 
P

Pete Biggs

Guest
Simon Brooke wrote:
> in message <[email protected]>, elyob
> ('[email protected]') wrote:
>
>> Nothing to do with the fact that our streets are too shite to skate
>> on then? They could just skate around the park .. unless they are
>> put in inappropriate places?

>
> This takes us straight back to land rovers and green lanes. The
> streets of London are not engineered to a lower standard than the
> surfaced walks in the park. On the contrary, they're engineered to a
> much higher standard. But the walks are smooth enough to skate on and
> the streets are not. Why is this? Because damage to the road scales
> with the fourth power of axle weight.
>
> The park paths are in good condition because they have very few heavy
> vehicle movements. Consequently they don't get worn out.


The London streets are worse mainly because they're constantly dug up for
gas, electric and communications cables and only repaired crudely
afterwards. Some areas haven't been completely resurfaced for years.
Sunken drain and manhole covers are also a serious problem.

Smoothness of tarmac varies as well. The best tarmac in the parks is
smoother than a lot of new road surfaces (partly explaining why it's so
pleasant to cycle or skate on them). I suppose not so much grip is
required in the parks.

~PB
 
S

Simon Brooke

Guest
in message <[email protected]>, Paulmouk ('paulmo
Rusty Car [email protected]') wrote:

>
> "Matt B" <[email protected]> wrote in message
> news:[email protected]
>> Simon Brooke wrote:
>>>
>>> This takes us straight back to land rovers and green lanes. The
>>> streets of London are not engineered to a lower standard than the
>>> surfaced walks in the park. On the contrary, they're engineered to a
>>> much higher standard. But the walks are smooth enough to skate on and
>>> the streets are not. Why is this? Because damage to the road scales
>>> with the fourth power of axle weight.

>>
>> Isn't it influenced by footprint size, thus affecting the pressure
>> applied? A slim woman does more

>
> Road strength/thickness/material is based on the forecast no. of
> million standard lorry axles per year.
> Motorways , distributor roads, residential roads, park roads,
> pedestrian paths etc etc are not all designed and built to be the same
> strength.


That's what I said, isn't it?

--
[email protected] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; It's dangerous to be right when the government is wrong.
;; Voltaire RIP Dr David Kelly 1945-2004
 
B

badger

Guest
Anthony Jones wrote:
> Your vague arm waving calculation is unnecessary, just look at the
> respective tyre pressures. A MTB will typically use around 30psi. I
> suspect this isn't massively different from that a Landrover would use.
>
> Anthony

30psi? my MTB needs 50-60 or I get pinch punctures...
 
A

Anthony Jones

Guest
badger wrote:
>> Your vague arm waving calculation is unnecessary, just look at the
>> respective tyre pressures. A MTB will typically use around 30psi. I
>> suspect this isn't massively different from that a Landrover would use.
>>
>> Anthony

> 30psi? my MTB needs 50-60 or I get pinch punctures...


Never really had a problem at 30-40psi myself (with 2.3in tyres IIRC).
Evidently YMMV. :)

Anthony
 
D

Dave Larrington

Guest
In article <[email protected]>, Pete Biggs
([email protected]) wrote:
> Simon Brooke wrote:
> > in message <[email protected]>, elyob
> > ('[email protected]') wrote:
> >
> >> Nothing to do with the fact that our streets are too shite to skate
> >> on then? They could just skate around the park .. unless they are
> >> put in inappropriate places?

> >
> > This takes us straight back to land rovers and green lanes. The
> > streets of London are not engineered to a lower standard than the
> > surfaced walks in the park. On the contrary, they're engineered to a
> > much higher standard. But the walks are smooth enough to skate on and
> > the streets are not. Why is this? Because damage to the road scales
> > with the fourth power of axle weight.
> >
> > The park paths are in good condition because they have very few heavy
> > vehicle movements. Consequently they don't get worn out.

>
> The London streets are worse mainly because they're constantly dug up for
> gas, electric and communications cables and only repaired crudely
> afterwards. Some areas haven't been completely resurfaced for years.


s/years/decades/ There's a few places on my commute where the cobbles
are showing through.

--
Dave Larrington - <http://www.legslarry.beerdrinkers.co.uk/>
I thought I saw his name on a jar of marmalade the other day, but when I
looked more closely, I saw it read 'thick cut'.
 
P

POHB

Guest
> Most of the police I see in the Parks these days are driving up and
> down the Serpentine Road,


I saw a convoy of about a dozen bobbies on bikes there a few months back. I
wondered what they were doing. Do they have training runs for bike police?
 
A

Alan Holmes

Guest
"Anthony Jones" <[email protected]> wrote in message
news:[email protected]
> badger wrote:
>>> Your vague arm waving calculation is unnecessary, just look at the
>>> respective tyre pressures. A MTB will typically use around 30psi. I
>>> suspect this isn't massively different from that a Landrover would use.
>>>
>>> Anthony

>> 30psi? my MTB needs 50-60 or I get pinch punctures...

>
> Never really had a problem at 30-40psi myself (with 2.3in tyres IIRC).
> Evidently YMMV. :)


I had to use at least 60 psi for my Raleigh!

Alan

>
> Anthony
 
A

Alex R

Guest
In article <[email protected]>,
"POHB" <[email protected]> wrote:

> > Most of the police I see in the Parks these days are driving up and
> > down the Serpentine Road,

>
> I saw a convoy of about a dozen bobbies on bikes there a few months back. I
> wondered what they were doing. Do they have training runs for bike police?


<delurk>
The standard met police bike course is 2 days long and you do a couple
of rides about in convoy during it. The course assumes no experience
whatsoever of cycling so the instructors have to make sure you are okay
in traffic, etc.

Alex
</delurk>
 
C

Chris Malcolm

Guest
Matt B <[email protected]> wrote:
> Simon Brooke wrote:
>>
>> This takes us straight back to land rovers and green lanes. The streets
>> of London are not engineered to a lower standard than the surfaced walks
>> in the park. On the contrary, they're engineered to a much higher
>> standard. But the walks are smooth enough to skate on and the streets
>> are not. Why is this? Because damage to the road scales with the fourth
>> power of axle weight.


> Isn't it influenced by footprint size, thus affecting the pressure
> applied? A slim woman does more damage to a wooden floor in stilettos
> that a fat bloke does in carpet slippers.


No, because the problem with roads isn't denting the surface, it is
collapsing the underlying weight-bearing foundations, so footprint
doesn't matter and load on the wheel axle does, where having two
adjacent wheels counts as having one of twice the wheel load.

--
Chris Malcolm [email protected] +44 (0)131 651 3445 DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]