Rough winter terrain, just how long will it take you to walk a mile here? Photograph by Kathleen Reynolds, used with permission.
I
actually started writing this article more than 20 years ago, I just never
finished it –
Author’s Note
Did
you ever notice that it takes longer to bushwhack through heavy brush or to
stomp through deep snow, than it does to walk alongside a road? Did you ever wonder how long it takes to walk
a mile in the wilderness?
The distance, speed and time triangle, graphic by the Author.
A
hike or a walk in the wilderness is often measured in the time it takes to
cross the distance, rather than in the distance itself. This is because of all the things that can
slow you down in the wilderness, things like rough terrain, climbing up or down
hills, brush, heat, snow, sand, mud, or darkness, to name a few.
So,
just how long does it take to walk a mile, anyways?
Well,
W. W. Naismith developed a handy rule of thumb to help you to estimate how long
it will take you to travel through the wilderness, way back in 1892.1
The first appearance of Naismith’s rule, from Scottish Mountaineering Club Journal, Volume 2, 1893, page 136.
Naismith’s
basic rule of thumb states that as a base line time a walker can walk 3 miles
(5 km) in an hour along a path, however the walker will incur a time penalty, adding
one hour to the base time for every 2,000 feet (600 meters) of ascent that he
or she makes.
Now,
Naismith was an optimist, and he created his rule of thumb for reasonably fit
walker, travelling through typical hill country, in typical weather, along a
relatively flat, clear, and level path.
It is important to remember that Naismith’s rule gives a reasonable minimum
estimate of the time require to complete a hike.2
Refinements,
corrections, modifications...they’re everywhere!
For
many years people have been trying to refine or correct Naismith’s basic rule,
so that it gives a more correct estimate of the time needed to complete a
walk. Some people have come up with
corrections due to the difficulty of the path or the level of the physical
fitness of the walker, others with modifications that correct for steep
descents, an issue that Naismith didn’t address, this is important because when
ascending or descending a steep slope a person naturally takes shorter steps or
they will zigzag up or down the hillside on switchbacks, and this increases the
distance traveled while reducing the slope.
R. Aitken, in his 1977 PhD thesis, suggested 3 miles (5 km) of travel
per hour could only be achieved on roads or good paths and that on all other
ground, the base distance should be reduced to 2-½ miles (4 km) per hour. Longmuir, in his 1984, book Mountaincraft
and Leadership, offered another refinement when he suggested the following
time penalties, subtracting 10 minutes from the base time for every 1,000 feet
(300 meters) of descent along slopes between 5o to 12o,
and when descending slopes greater than 12o, adding 10 minutes to
the base time of travel for every 1,000 feet (300 meters) of descent.3 Bob Wirth suggested in Backpacking in the 80’s,
as a rule of thumb, that it will take you twice as long to hike up a steep
trail as it will to hike back down. And
even the Unites State Army got into the act, writing in Mountain Operation, FM
90-6, (1980), that because of the steeper slopes found in mountainous areas
that a time penalty of one hour should be added when ascending 1,000 feet (300
meters) or when descending 2,000 feet (600 meters) of elevation.4
So, which
should I use?
An excerpt from Wolseley, General Viscount; The Soldier’s Pocket-Book For Field Service, by Wolseley, General Viscount, page 323 to 324.
So,
just what corrections, modifications or refinements should you use when
planning your route and estimating how long it will take to complete your
travels. Well, do what everyone else has
done and add your own modifications, corrections, and refinements to Naismith’s
basic rule of thumb.
An excerpt from Wolseley, General Viscount; The Soldier’s Pocket-Book For Field Service, by Wolseley, General Viscount, page 323.
It
is important to remember that Naismith’s Rule includes a built-in 5 to 10
minute rest break, or halt, every hour to tie shoes, adjust pack straps, drink
some water, etc. Also, if you are low on
water, spend your break purifying some more, so that you will have something to
drink on your next break. On hikes
longer than 5 hours, add in a 30-minute rest break at the halfway point for
lunch, this will help combat the effects of fatigue.
Graphic by the Author.
Here
are some suggestions for corrections you might like to consider, from various
sources5, when creating your own modifications to Naismith’s Rule.
Base Times
Good
path 3
mph or 5 kmph
Rough
path 2-½
mph or 4
kmph
Scrambling6
up steeps slopes 2 mph or 3
kmph
Walking
through the forest 1-½ mph or 2
kmph
without a trail and no
undergrowth
Bushwhacking
through dense 1 mph or 1-½
kmph
undergrowth or
rough terrain
* All of these base times
assume that you are carrying than a light pack of no more than 40 lbs. (18 kgs)
Time Penalties
Walking
at night Add
20 minutes per hour
For
every 10 lbs. (4.5 kg) over Add 10
minutes per hour
40 lbs. (18 kg) carried
When
the temperature is Add 5
minutes per hour
between 67o F – 77o
F
(19o C – 25o C)7
When
the temperature is Add 10
minutes per hour
between 77o F – 87o
F
(25o C – 31o C)
When
the temperature is Add 20
minutes per hour
between 87o F – 97o
F
(31o C – 36o C)
For
every 5 hours hiked Add 1
hour
without a long break,
due to fatigue
You
are an inexperienced Add 10 minutes
per hour
or out-of-shape hiker8
For
every 2,000 feet (600 m) Add 1
hour
of ascent on slopes
between 5o and 12o
For
every 1,000 feet (300 m) Add 1
hour
ascent on slopes
greater than 12o
For
every 1,000 feet (300 m) Subtract
10 minutes per hour
descent on slopes
between 5o and 12o
For
every 1,000 feet (300 m) Add 10
minutes per hour
descent on slopes
greater than 12o
Now
that you have modified Naismith’s rule of thumb, get out into the wilderness,
and test it. Measure how long it takes
you and if you are within 5% of the time you estimated, then you have estimated
correctly, if not try some more or different modifications, refinements, and
corrections, until you get it right!
But what
about when I’m not hiking, or in the winter...
“But
what about when I’m not hiking, what if I am canoeing”, you ask, “And,
what if it is in the winter and I am snowshoeing, or cross-country skiing”?
Good
questions. Let’s talk about them. Oh, and by the way whenever you are on foot,
winter, spring, summer or fall, the earlier modifiers for hiking apply, so if
you are wearing a 60-pound (27 kg) pack, are climbing or descending in
elevation, whether you are tramping over a portage, or walking across a snowy
field, remember that the earlier time penalties still apply.
When
canoeing, allow for the following travel rates.
Base Times
Open
lakes with no portages 3 mph or 5
kmph
Mixed
lakes and portages 2 mph or 3
kmph
Portages 1 mph or 1-½
kmph
Creeks
and winding rivers 1 mph or 1-½
kmph
Time Penalties
For
every 5 hours canoed Add
1hour
without a long break,
due to fatigue
Portaging
on a poorly Add 10
minutes per hour
maintained portage
Portaging
on an unmaintained Add 20 minutes
per hour
portage
Inexperienced
or out-of-shape Add 10 minutes per
hour
canoers
And
don’t forget, that multiple trips over the same portage doesn’t just double the
distance and time it triples it! For
more see “Algonquin Portaging 101 ©”, HERE.
The effect of multiple trips over the same portage on time and distance, graphic by the Author.
During
the winter, the depth of the snow can seriously affect the time it takes to
cover a distance. And wearing snowshoes
or cross-country skis, while they keep you from sinking in the snow, can change
the base rate of travel. The Basic
Cold Weather Manual, FM 31-70, from 1968, covers this very well.
Basic Cold Weather Manual, FM 31-70, page 61
Some other things
to remember
Photograph by the Author.
According
to Bob Wirth’s Backpacking in the 80’s, you should allow one hour of
daylight for waking up, cooking breakfast and breaking camp and one to two
hours for setting up camp and cooking dinner.
During the winter, in the northern hemisphere, you only have about six
to seven hours of daylight and during the summer you will have between nine and
eleven hours of sun light – so plan accordingly.
Don’t forget to come back next week and read “The Top Ten Wilderness
Survival Skills...Number Eleven©”, where we will talk about all the survival
skills that didn’t fit into my top ten list.
I
hope that you continue to enjoy The Woodsman’s Journal Online and look for me
on YouTube at BandanaMan Productions for other related videos, HERE. Don’t forget to follow me on both The
Woodsman’s Journal Online, HERE,
and subscribe to BandanaMan Productions on YouTube. If you have questions, as always, feel free
to leave a comment on either site. I
announce new articles on Facebook at Eric Reynolds, on Instagram at
bandanamanaproductions, and on VK at Eric Reynolds, so watch for me.
That
is all for now, and as always, until next time, Happy Trails!
Notes
1
William Wilson Naismith was born near Glasgow, Scotland in 1856. He worked in insurance his whole life;
however, he is best known as a mountaineer, rock climber, skier, and meteorologists. In 1899, he helped to create the Scottish
Mountaineering Club. He died in 1935, at
the age of 79.
From
“It's Time To Head For The Hills”, by Toby Shergold.
2
“Modelling Naismith’s Rule”, Steffen Fritz and Steve Carver.
3
Ibid.
4
An excerpt from Mountain Operations, FM 90-6, by the Department of the Army.
The
steepness or degree of a slope is vague or arbitrary classification that is often
arbitrary, with little agreement between experts. However, the U.S. Geological Survey defines
gentle slopes as slopes which are less than 15%, moderate slopes, which are
somewhat more difficult to climb or descend, as slopes from 15% to 50% (or 8-½o
to 26-½o), and steep slopes, to be slopes greater than 50% (or
almost 30o) up to 100%, (or 45o). These last slopes are difficult to climb and
often must be crossed by scrambling up or down using your hands.
The
greater the slope, the greater the difficulty in ascending or descending the
hill or mountainside.
As
page 1-3 of Mountain Operations notes, in mountainous areas, which are
landforms where the local relief or distance from the valley floor to the summit
is greater than 1,000 ft (300 meters) and in hill country where the local
relief is less than 1,000 feet (300 meters) more than 50% of the slopes that
you will encounter will be moderate to steep slopes greater than 15% or 8-½o. The more mountainous the area, the steeper
the slopes are likely to be.
An excerpt from Hillside Materials and Slopes of the San Francisco Bay Region, California, Stephen D. Ellen, and Carl M. Wentworth.
As
a steepness comparison, correct slope for a ladder is a 4:1 ratio, or a slope
of approximately 75o.
From
Mountain Operations, FM 90-6, by the Department of The Army, Hillside
Materials and Slopes of the San Francisco Bay Region, California, by
Stephen D. Ellen, and Carl M. Wentworth, and Final
Environmental Impact Statement, Proposed Southern California Lease Offering
April, 1984, Department of the
Interior.
5
From Winter Wise, Travel and Survival in Ice and Snow, by Montague Alford;
Mountain Operations, FM 90-6, June 30, 1980, by the Department of the
Army; “Modelling Naismith’s Rule”, by Fritz Steffen, and Steve Carver; Backpacking
in the 80’s, by Bob Wirth; The Soldier’s Pocket-Book For Field Service,
by General Viscount Wolseley, and “The Art of Navigation”, (unfortunately this
website is no longer available).
6
Scrambling has been defined by some as hiking that requires the use of hands,
but not ropes. It is a vague term to
describe an activity that lies somewhere between hiking, easy mountaineering,
and rock climbing.
7 The
Soldier’s Pocket-Book For Field Service, by General Viscount Wolseley
8
According to “The Art of Navigation”, which unfortunately is no longer
available, very fit, and experienced hikers can reduce the total time traveled
by 1/3.
Sources
Alford,
Montague; Winter Wise, Travel and Survival in Ice and Snow, [Heritage House
Publishing Company Ltd., Surrey, B.C., 1999], page 49
Department
of the Army, Basic Cold Weather Manual, FM 31-70, April 12, 1968,
[Paladin Press, Boulder, CO, 1974], page 61
Department
of the Army,
Mountain Operations, FM 90-6, June 30, 1980, [Washington,
DC, June 30, 1980], page 1-3
Douglas, William, Editor;
Scottish Mountaineering Club Journal, Volume 2,
[The Scottish Mountaineering Club, Edinburgh, 1893], page 136, https://books.google.com/books?id=-hn0Xst3g_gC&pg=PA136&dq=%22this+tallies+exactly+with+a+simple+formula%22&hl=en&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwie2PqqxqP2AhVPonIEHUpHCpMQ6AF6BAgLEAI#v=onepage&q=%22this%20tallies%20exactly%20with%20a%20simple%20formula%22&f=false,
accessed February 28, 2022
Ellen, Stephen D. and
Wentworth, Carl M.; Hillside Materials and Slopes of the San Francisco Bay
Region, California, U.S. Geological Survey, Professional Paper 1357,
[United State Government Printing Office, Washington, D.C., 1995], page 13 to
14, https://books.google.com/books?id=mBuac6RrOJMC&pg=PA14&dq=slope+%25+steep+gentle&hl=en&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwiAv6u9n6b2AhUzp3IEHaz2DMwQ6AF6BAgDEAI#v=onepage&q=slope%20%25%20steep%20gentle&f=false, accessed March 1, 2022
Fritz, Steffen, and Carver, Steve; “Modelling
Naismith’s Rule” School of Geography, University of Leeds, http://www.geog.leeds.ac.uk/papers/98-7/,
accessed February 28, 2022
Shergold, Toby, “It's Time To Head For The Hills”,
The Independent, March 29, 2003, https://www.independent.co.uk/travel/news-and-advice/it-s-time-to-head-for-the-hills-5352619.html, accessed February 28, 2022
Wirth,
Bob; Backpacking in the 80’s, [Parker Publishing Company, Inc. West
Nyack, NY, 1984], page 147-149
Wolseley,
General Viscount; The Soldier’s Pocket-Book For Field Service, [MacMillan
and Co, London, 1886], page 323 to 324, https://books.google.com/books?id=uz9FAAAAYAAJ&printsec=frontcover&dq=the+soldier%27s+pocket-book+for+Field+Services+1886&hl=en&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwj-4MvIsJ72AhU8knIEHfQnB3MQ6AF6BAgJEAI#v=onepage&q=the%20soldier's%20pocket-book%20for%20Field%20Services%201886&f=false, accessed February 26,
2022.
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