Messages

1

New Member Introductions / Re: Change in the Earth's magnetic position.

« on: February 05, 2017, 12:34:05 PM »

Hi Terry,

Welcome to the Forum.  Its bit slow these days but still a great resource. If you do a search on past threads and post you will find information on the subject. 

To answer your question.  Any OS map is obsolete on the day it was sent to the printers let alone the day it is published.  Changes are continuous.  New roads and all that. 

In reality the very small change in magnetic field is not significant in the short term.  Which means if you are using a current map then all is well.  There is no way you are going to be measuring 0.25 of a degree on a hand held compass.  However, the changes do build up as the years roll by and information given on a ageing map is going to become increasingly inaccurate.  Both in terms of magnetic data and topographical data.  Bottom line always use a current map.

Lost Soul

2

General Discussion / Re: Merry Christmas

« on: December 26, 2016, 12:53:08 PM »

Yes, merry Christmas and a happy new year to all.

Lost Soul.

3

General navigational Kit / Re: Marking Harveys Maps

« on: December 26, 2016, 12:48:55 PM »

Hi Brynglas

Are the maps plasticised?  If so then in my experience the only means of marking plasticised  maps is with a chinagraph pencil or lumograph pens.  But both tend too rub of easily when the map is being used.  Ughh!.  The best way to clean the map is with furniture polish or meths.

If the map is paper then a B6 pencil is very good.  Normal soft eraser cleans them up quite nicely with little residual damage.

Hope this helps.

 

4

General Discussion / Re: foreshortening effect

« on: April 18, 2016, 09:33:58 PM »

Ah ha.  As you say CP spurious precision and how does one access tables etc when out on the hill.  The ability to climb a hill and the time taken is variable from person to person.  Condition of surface, weather conditions, snow cover, personal fitness, tiredness levels, stopping to get your breath back, weight of pack and even weight of foot ware all have an impact too.  A lb on the feet is equal to 5 lb on your back.  Muddy boots vs dry ones.  Which all has to be hauled upwards.

Methodologies for compensating for the foreshortening effect are Naismith's Rule which is really what the UNM is dealing with and then there is Tranters variations to it.  Interestingly Hugh Westacott in his "The Walkers Handbook" 5th Edition deals with the subject.  In essence he say the same as you CP. 

Its all a load of academic tosh.  And only relevant to the fit and experienced in defined conditions.  As far as I am concerned best to do your own trials with your normal gear and pack weight over different slopes and see what you get in terms of pacing and time.  Both for dry and slippery muddy slopes and snow cover.  As a staring point Hugh suggests 15 min to walk 1 km plus 1.5 minutes for every 10m contour crossed and 2.5 minutes for 15m contour intervals.

Pacing in my own case is 72 steps per 100m on the flat reasonable surface.  Get to a bit of a steep slope then its at least 88 paces and if muddy much steeper approaching a 100.  As to precision timing more or less forget it in those types of conditions.

Hope this helps

5

General Discussion / Re: bearing/GPS/Map differential

« on: April 18, 2016, 08:27:30 PM »

Hi Which Way,

Better to make errors in the relative safety of your own training environment and discuss them in this forum so we can all learn.  Than have a Coroner trying to second guess what went wrong, and probably getting it wrong too. 

Lost Soul.

6

New Member Introductions / Re: Hello from the Forest

« on: December 27, 2015, 10:02:38 AM »

Do you have to use 50K?  25K is, I am sure you know, significantly more detailed and hence much better for on foot activities.

7

New Member Introductions / Re: Hello from the Forest

« on: December 26, 2015, 07:14:31 PM »

Welcome to a very useful, polite, helpful and friendly forum.  Its been a bit slow of late but there are many useful threads with lots of very good information.  Si if you don't get an immediate answer to your question you might want to check out some of the earlier threads.

Lost Soul

8

General Discussion / Re: cattle

« on: September 04, 2015, 07:51:13 PM »

Thanks for the clarifications Hugh.

LS

9

General Discussion / Re: cattle

« on: September 04, 2015, 05:12:03 PM »

Now I recall someone saying its to do with the law.  There are laws about dangerous cattle breads, footpaths and public protection.  The law specifies affected breads that must not be kept on land legally accessed by the general public.  Breads specified were those resident in the UK at the time the law was passed.  However, farmers seem to be importing breeds that are problematic in respect of public safety, and as they are not specifically referenced in the appropriate legislation then they are by default exempt.

A quirk of UK law.  Same problem as trying to control legal highs.

If you don't specify what ever is the problem then its not illegal.

The law needs to be written in generic terms viz Cattle shall not be kept in areas legally accessed by the general public unless they have been certified by the HSE as being docile and safe when in the proximity of other life forms.  You get the gist.

10

General Discussion / Re: cattle

« on: September 02, 2015, 05:24:11 PM »

Hi WW

For starters have a look at this thread.

http://micronavigation.com/forum/index.php?topic=695.0

You might like to do a search of the Forum for cattle.  If I recall correctly the subject has cropped on more than one occasion.

LS

11

Maps / Re: map symbols

« on: August 31, 2015, 09:40:46 AM »

Hi Which Way,

Welcome to a very friendly and useful forum.  Its been a bit slow of late, but still very useful non the less.

Picking up on Hugh's comments of changed landscape vs survey dates.  Have been caught out on more than one occasion by the disappearance of many acres of forest (harvested) and on the other hand by (young) forests appearing out of no where.  Well they had been planted since the map was last surveyed.

Lost Soul   

12

Satnav (GPS GLONASS COMPASS Galileo) / Re: Handheld satnavs and GNSS

« on: August 26, 2015, 10:06:12 AM »

Hi Hugh,

Thanks, useful reviews you seem to have hit the nail on the head.

LS

13

Satnav (GPS GLONASS COMPASS Galileo) / Re: Handheld satnavs and GNSS

« on: August 25, 2015, 12:57:18 PM »

Hi Hugh,

Your link to the book reviews, "here", doesn't work.

LS

14

Satnav (GPS GLONASS COMPASS Galileo) / Re: Handheld satnavs and GNSS

« on: August 24, 2015, 10:18:52 AM »

Hi Hugh,

The subject of compatibility and interoperability of Sat Navs and the various satellite constellations has been the subject of some debate at various time on this forum.   I think your proposed note is about right.  Might I suggest that you try and elicit a response from Captain Paranoia.  He seems to have extensive knowledge on these matters.

Congratulations on your sales figures.

Regards

Lost Soul.

15

Maps / Re: Fascinating Soviet maps

« on: July 22, 2015, 09:40:55 AM »

Thanks Hugh,

What beautiful maps.  To support the comments about civilian maps being un representative.  I have a tourist map of Moscow from the early 80.  In some places very inaccurate indeed.  So it made using it difficult.  One of the most bizarre things about it was the square that hosted the Lubyanka, the KGB HQ and prison.  Said place is on the north side of the square.  The east, south and west side mapping was accurate.  But the North totally different, buildings side streets, road junctions etc were missing.  The map was nothing like the urban landscape.

Have heard similar tales of official visiting scientific expeditions being totally confused as to position etc due to suspected deliberately inaccurate local mapping.