Field tests of equipment for preparing snow roads and ice landings

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Field tests of equipment for preparing snow roads and ice landings Ager, B. H:son

NATIONAL RESEARCH COUNCIL CANADA

D I V I S I O N O F B U I L D I N G RESEARCH

P I E L D T E S T S O P EQUIPMENT POR PREPARING SNOW ROADS AND I C E LANDINGS

by B. H : s o n A g e r I n t e r n a l R e p o r t

no.

253

of t h e D i v i s i o n of B u i l d i n g R e s e a r c h OTTAWA A p r i l 1962

PREFACE

Snow and i c e a r e not commonly regarded a s building m a t e r i a l s , b u t they a r e an e s s e n t i a l p a r t of t h e t e r r a i n of Canada, and, l i k e muskeg, permafrost, s o i l , rock and water pose engineering problems which merit s p e c i a l study. They play an important p a r t i n t h e woods operations of paper companies since i n winter roads

must

be made over snow, and t h e i c e covers on lakes and r i v e r s a r e used a s landings f o r the p i l i n g of pulpwood. The Division of Building Research has through i t s Snow and Ice Section been carrying out s t u d i e s i n the laboratory and, with t h e c o l l a b o r a t i o n of paper companies, i n the f i e l d , on t h e bearing s t r e n g t h of i c e covers. An opportunity t o extend these s t u d i e s t o t h e making of snow roads and the preparation of landings and a l s o t o l e a r n a t f i r s t hand of Swedish p r a c t i c e s mas pre- sented when a young Swedish f o r e s t r y engineer i n t e r e s t e d

i n

these problems was awarded a Post-Doctorate Fellowship t o spend a year i n Canada with t h e Division. Some t r i a l s of equipment which he c a r r i e d out i n the f i e l d with t h e co- operation of one of t h e Canadian paper companies a r e now reported.

Ottawa

FIELD TESTS OF EQUIIUENT FOR PREPARING SNOW ROADS AND ICE LANDINGS

B. H:son Ager

I n r e c e n t y e a r s t h e r e have been some advances i n Sweden i n t h e d e s i g n of equipment used f o r p r e p a r i n g snow r o a d s and i c e landings.* During t h e w i n t e r of 1960-61, t h e a u t h o r had t h e o p p o r t u n i t y t o compare t h e performance of

some of t h i s equipment w i t h equipment which i s used o f t e n i n Canada f o r t h e same purpose. The comparisons were made on t h e l i m i t s of t h e A b i t i b i Co. a t I r o q u o i s F a l l s , Ontario. I n s p i t e of t h e f a c t t h a t o n l y a few p i e c e s of equipment were a v a i l a b l e f o r s t u d y , and t h a t t h e t e s t s were conducted i n o n l y one t y p e of snow, it was considered t h a t t h e observa- t i o n s should be recorded a s t h e y might be u s e f u l f o r subsequent i n v e s t i g a t i o n s and might a s s i s t l o g g i n g e n g i n e e r s in t h e i r

d e c i s i o n s r e g a r d i n g t h e c o n s t r u c t i o n of snow r o a d s and i c e landings.

General i n f o r m a t i o n on t h e p r e p a r a t i o n of snow r o a d s and i c e l a n d i n g s a s w e l l a s a summary of r e s u l t s and e x p e r i e n c e s o b t a i n e d from t e s t s on methods and equipment

conducted by t h e a u t h o r i n Sweden and i n Canada, was presented a t t h e March 1961 meeting of t h e Canadian Pulp and Paper

A s s o c i a t i o n (1). The above p a p e r c o n t a i n s a l s o t h e informa- t i o n r e q u i r e d t o make p r a c t i c a l d e c i s i o n s on t h e choice and use of equipment f o r snow compaction and i c e l a n d i n g p r e p a r a - t i o n . The p r e s e n t r e p o r t c o n t a i n s t h e r e s u l t s of t h e t e s t s conducted a t I r o q u o i s F a l l s and some d i s c u s s i o n of s p e c i f i c l o c a l problems, n o t g i v e n i n r e f e r e n c e (1).

TESTS ON SNO'A' COMPACTION EQUIRI~ENT

D e s c r i p t i o n of t h e Equipment Tested ( F i g s . 1, 2 )

Weight Width Diam. S t a t i c r o l l e r s : l a r g e (wooden) 12,400 l b 16' 7'4" medium (wooden) 4,200 l b 151 316,' small ( c u l v e r t Pipe 730 l b 1414" 210" 3,370 l b 5'9"

-

V i b r a t o r

*

Temporary s t o r a g e a r e a f o r l o g s on t h e i c e c o v e r of r i v e r s o r l a k e s .

Compaction T e s t s

The primary purpose of t h e compaction t e s t s was t o compare t h e q u a l i t y ( b e a r i n g p r o p e r t i e s ) of snow compacted with t h e v i b r a t o r and with conventional r o l l e r s . Short t e s t

s t r i p s were prepared i n v i r g i n snow on t h e i c e cover of a lake. The equipment was u s u a l l y towed a t t h e normal working speed of 5 t o 6 mph. i k e snow was compacted by one, two o r t h r e e passes of t h e equipinent. The compacted snow was allowed t o harden f o r about 24 hr before observations were made on t h e snow p r o p e r t i e s . i k e following observations were used a s i n d i c a t o r s of t h e road q u a l i t y :

Snow D e n s i t s

This was measured i n t h e upper 4 i n . of t h e road

1

bed with a 250-cm' sampler. Figures given a r e u s u a l l y t h e average of f o u r samples.

P r o c t o r Hardness 2

A 1-cm c i r c u l a r p l a t e was pressed v e r t i c a l l y on

t h e snow s u r f a c e , and t h e pressure r e q u i r e d t o c o l l a p s e t h e snow was recorded. Figures given a r e t h e average of 15 i n d i v i d u a l observations.

Ram Hardness

A 60' cone was f o r c e d through the snow by dropping a weight on it from a given height. The average r e s i s - tance t o p e n e t r a t i o n was observed. Figures given a r e t h e average of f o u r i n d i v i d u a l observations.

Shear S t r e n g t h

A s h e a r vane was i n s e r t e d i n t o t h e snow t o a depth of 1 i n . from t h e upper p a r t of t h e vane t o t h e snow s u r f a c e . i k e vane was t w i s t e d with a torque wrench,

and t h e f o r c e required t o c o l l a p s e t h e snow was recorded. Figures given a r e t h e average of f o u r i n d i v i d u a l observa- t i o n s .

The r e s u l t s of t h e s e t e s t s a r e shown i n Fig. 3. The undisturbed snow was very coarse-grained, (20 p e r c e n t shape

II d tt

,

very f i n e t o f i n e , 80 p e r c e n t shape " e f t , medium t o very

coarse according t o t h e I n t e r n a t i o n a l Snow C l a s s i f i c a t i o n ( 2 )) with a d e n s i t y of 0.18 average and a depth between 6 t o 10 i n . During t h e t e s t a i r temperatures ranged between O0 and -lO°F. Figure 3 shows t h a t f o r t h e snow and weather c o n d i t i o n s t h a t P r e v a i l e d , t h e v i b r a t o r produced a compacted snow s t r i p with d e n s i t y and s t r e n g t h p r o p e r t i e s between those obtained with

t h e l a r g e r o l l e r and t h e medium r o l l e r . When t h e v i b r a t o r was towed w i t h t h e v i b r a t i n g mechanism t u r n e d o f f , t h e r e s u l t s of compaction were comparable t o t h o s e obtained w i t h t h e medium r o l l e r .

Another t e s t was c a r r i e d o u t a t t h e same p l a c e t o determine if t h e speed a t which t h e v i b r a t o r was towed would a f f e c t t h e p r o p e r t i e s of t h e compacted snow. Three d i f f e r e n t speeds were used. The d e n s i t y of t h e compacted snow i n c r e a s e d w i t h d e c r e a s i n g speed, ( P i g . 4 ) b u t t h e e f f e c t i s s o s m a l l t h a t i n p r a c t i c a l work it would be b e t t e r t o make two passes with t h e v i b r a t o r r a t h e r t h a n tow it a t a low speed.

Concurrent w i t h t h e t e s t s on t h e e f f e c t of speed, a l a n e was compacted w i t h t h e b i g r o l l e r p a r a l l e l t o t h e s p e e d - t e s t r o a d s , and i t s p r o p e r t i e s measured. This time t h e v i b r a t o r produced compacted snow w i t h p r o p e r t i e s s i m i l a r t o t h o s e obtained w i t h t h e b i g r o l l e r ( P i g . 4 ) . This second comparison confirmed t h a t t h e v i b r a t o r was, on t h e whole, n o t a s e f f e c t i v e a s t h e b i g r o l l e r .

Compaction t e s t s w i t h t h e v i b r a t o r were c a r r i e d o u t a l s o on a bush road. The purpose of t h e s e t e s t s was t o f i n d t h e maximum compacted d e n s i t y t h a t could be o b t a i n e d w i t h t h e v i b r a t o r under t h e p r e v a i l i n g c o n d i t i o n s . The t e s t was

c a r r i e d o u t i n 1 2 i n . of c o a r s e - g r a i n e d snow ( 1 0 p e r c e n t t y p e "d", f i n e t o medium, 90 p e r c e n t t y p e "el1, medium t o v e r y

c o a r s e ( 2 ) ) w i t h a n average u n d i s t u r b e d d e n s i t y of 0.14. S i x c o n s e c u t i v e p a s s e s w i t h t h e v i b r a t o r produced compacted snow w i t h a d e n s i t y of 0.46, which i s d e f i n i t e l y t o o low f o r t r u c k t r a f f i c f o r t h i s type of snow. It should be p o i n t e d o u t t h a t t h e snow c o n d i t i o n s f o r a l l of t h e t e s t s a t I r o q u o i s F a l l s were e x c e p t i o n a l l y unfavourable f o r snow compaction.

I t was found t h a t f o r t h e snow and weather condi- t i o n s d u r i n g t h e t e s t s , t h e v i b r a t o r , c o n s i d e r i n g b o t h i t s working width and t h e p r o p e r t i e s of t h e compacted snow, was n o t a s e f f e c t i v e f o r p r e p a r i n g snow r o a d s a s t h e heavy r o l l e r .

T e s t s on T r a v e l l i n g Speed and M o b i l i t y f o r D i f f e r e n t V e h i c l e s Towing t h e V i b r a t i n g Compactor

The purpose of t h e s e t e s t s was t o determine whether t h e t h r e e t y p e s of v e h i c l e s a v a i l a b l e were capable of towing t h e v i b r a t o r under t h e p r e v a i l i n g snow c o n d i t i o n s . _The

v e h i c l e s t e s t e d were t h e D4, t h e John Deere and t h e Bombardier 55. _{m e t e s t s were c a r r i e d o u t on a p r e v i o u s l y bulldozed}

bush r o a d , covered w i t h 1 2 i n . of v i r g i n , c o a r s e - g r a i n e d snow (10 p e r c e n t type "dl1, f i n e t o medium, 90 p e r c e n t t y p e "eft 9

medium t o v e r y c o a r s e ( 2 ) ) with a n undisturbed d e n s i t y of 0.14. The t e s t s i t e had a 1 p e r c e n t s l o p e , and t h e t e s t s were

run

w i t h t h e v e h i c l e s t r a v e l l i n g downhill. Speed was measured when t h e v e h i c l e s were towing t h e v i b r a t o r a l o n g a s t r a i g h t p a t h i n a g e a r t h e o p e r a t o r c o n s i d e r e d most s u i t a b l e f o r t h e work. The a b i l i t y of t h e v e h i c l e t o t u r n w i t h t h e compactor i n tow was a l s o observed. The observed speeds and t h e

a b i l i t y t o make t u r n s a r e shorm i n Table I.

TABLE I

SPEED AND hlOBILITY FOR DIFFERENT VMICLES

TOWING THE VIBRATOR

I t was concluded t h a t t h e 55 was n o t s u i t a b l e f o r towing t h e v i b r a t o r under t h e snow c o n d i t i o n s t h a t p r e v a i l e d , because of i t s i n a b i l i t y t o t u r n .

Vehicle

D4

John Deere

55

COMPARISON OF FLOODING PUl!tTPS

The purpose of t h e t e s t s on f l o o d i n g equipment was t o compare a r e c e n t l y developed powered a u g e r and l i g h t w e i g h t screw pump w i t h equipment a v a i l a b l e a t t h e t e s t a r e a . The new pump, t h e Typhon (Fig. 5 ) , had a c a p a c i t y of 60,000 gph, a weight of 45 l b , and was powered by a 4.3 hp a i r - c o o l e d

engine. The a u g e r f o r d r i l l i n g t h e i c e wei&ed 45 l b and had a n engine of t h e same kind a s t h e pump. The pumps w i t h which

it was compared were t h e Homelite, London and t h e Rex. These a r e a l l c e n t r i f u g a l pumps, t h e Homelite and London pumps

having a weight of 100 l b and a c a p a c i t y of 12,800 gph, w h i l e t h e corresponding f i g u r e s f o r t h e Rex pump were 500 l b and 40,000 gph. A l l t h e s e f i g u r e s a r e approximate. Speed when t r a v e l l i n g s t r a i g h t , mph 2.9 2.2 3.2 A t e s t on t h e f l o o d i n g a b i l i t y of t h e pumps was made on 4: i n . of compacted snow o v e r l y i n g 25 i n . of i c e . m e a i r temperature was a b o u t +5'F. The r e s u l t s a r e g i v e n i n Table 11. The f l o o d i n g a b i l i t i e s r e l a t i v e t o t h e Rex pump a r e shown i n t h e l a s t column.

Was a b l e t o t u r n

Ye s

Ye s

TABLE I1

OBSERVED WETTING CAPACITIES OF DIFFEEiENT

PUMPS

s I : w i t h conic n o z z l e

I1 : w i t h c y l i n d r i c a l n o z z l e

A comparison of t h e f l o o d i n g a b i l i t y was c a r r i e d o u t a l s o i n 1 0 i n . of v i r g i n , coarse-grained snow ( 2 0 p e r c e n t type

"d" v e r y f i n e t o f i n e , 80 p e r c e n t type " e n , medium t o c o a r s e ( 2 )

1

o v e r l y i n g

1 5

i n . of i c e . Although no measurements were made, it was a p p a r e n t t h a t under t h e s e c o n d i t i o n s t h e Rex pump was b e t t e r a b l e t o spread t h e w a t e r because of i t s

e l e v a t e d d i s c h a r g e . Flooding i n snow of t h a t d e p t h and kind however, h a s t o be considered a s a n e x c e p t i o n i n p r a c t i c a l work.

m

P

Hornelite London Rex Typhon I s k Typhon II* 1

A time s t u d y was made t o determine t h e s i z e of t h e crew t h a t would l i k e l y be r e q u i r e d t o o p e r a t e t h e Typhon a u g e r and pump. The r e s u l t s of t h e time s t u d y a r e g i v e n i n Appendix A.

Wetted a r e a , s q f t 1.350 1.350 4.500 5.700 5.750 T o t a l t i m e , min 7.8 8.0 10.0 10.0 10.0

Tihe h o l e s were n o t plugged a f t e r f l o o d i n g , s i n c e t h e

aim of t h e time s t u d y was t o analyze o n l y t h e h a n d l i n g of t h e pump. Plugging t h e h o l e s i s , i n p r a c t i c a l work, of g r e a t

importance when f l o o d i n g i s done with t h e Typhon pump. If it

i s n o t done most of t h e w a t e r m i l l r u n back through t h e h o l e and t h e q u a l i t y of t h e i c e r e c e i v e d a f t e r f r e e z i n g w i l l be very poor. I n Sweden, t h e h o l e s a r e g e n e r a l l y covered w i t h 1-ft sq p i e c e s of board and snow placed over t o p . According t o Swedish time s t u d i e s , t h i s p a r t of t h e work t a k e s 1 0 t o 20

Set depending on snow c o n d i t i o n s , e t c .

If t h e time f o r plugging t h e h o l e s and f o r normal d e l a y s i s i n c l u d e d , t h e time f o r h a n d l i n g t h e pumps,between h o l e s ( h o l e s p a c i n g 100 f t o r l e s s ) w i l l be a b o u t 1-2. min under a v e n g e c o n d i t i o n s , and 2 min ullder a d v e r s e c o n d i t i o n s . _Swedish

Sq f t p e r min 173 166 450 570 575 R e l a t i v e f l o o d i n g a b i l i t y 39 37 100 120 127

t e s t s i n d i c a t e t h a t t h e e f f e c t i v e pumping time from each h o l e should be a b o u t

5

min on t h i n i c e and 10 min on t h i c k i c e , and t h a t t h e pumping time should be g r a d u a l l y i n c r e a s e d

between t h e s e l i m i t s d u r i n g t h e period of p r e p a r a t i o n of t h e i c e landing. If t h e time consumption f o r b o t h pumping and h a n d l i n g i s c o n s i d e r e d , each pump w i l l f l o o d a t t h e r a t e of 1 0 t o 12 h o l e s p e r h r a t t h e beginning of t h e p r e p a r a t i o n

5

t o 6 h o l e s a t t h e end of t h e period. Time s t u d

period,

e s on t h e and powered a u g e r i n d i c a t e t h a t one man o p e r a t i n g one a u g e r can produce h o l e s f o r a t l e a s t f o u r pumps under most c o n d i t i o n s .

If t h e hole-producing c a p a c i t y of t h e a u g e r i s s l i h t l y below . t h e c r i t i c a l l i m i t , it i s more economical t o ex

dh?

en e pumping

time f o r each h o l e accordingljr, r a t h e r t h a n reduce t h e number of pumps. Considering t h e r e s u l t s of t h e time s t u d i e s and c o n s i d e r i n g a l s o Swedish e x p e r i e n c e s and t e s t s , one powered a u g e r and f o u r pumps, o p e r a t e d by a crew of t h r e e men i s probably t h e most e f f e c t i v e o p e r a t i n g u n i t .

!the f a c t o r t h a t u l t i m a t e l y determines which pump should be used f o r t h e p r e p a r a t o r y work i s i t s o p e r a t i n g c o s t .

A comparison of t h e t o t a l o p e r a t i n g c o s t s p e r flooded a r e a f o r t h e pumps should be based on i n f o r m a t i o n obtained from a c t u a l o p e r a t i o n s . This i n f o r m a t i o n was n o t a v a i l a b l e , b u t t h e

f o l l o w i n g e s t i m a t e was made t o show t h e approximate d i f f e r e n c e i n o p e r a t i n g c o s t s f o r t h e pumps t e s t e d . For each pump, one f a v o u r a b l e and one unfavourable a l t e r n a t i v e was chosen a s f o l l o w s :

Rex

-

A l t . I Crew: Two men o p e r a t e t h e pump. !the h o l e s a r e d r i l l e d w i t h a c h i s e l . The towing v e h i c l e needed t o move t h e pump i s used f o r t h i s work only.

A l t . I1 Crew: The sane a s i n A l t . I. !the towing v e h i c l e h a s o t h e r work b e s i d e s ( i . e . , snow removal o r compaction), and t h e time r e q u i r e d f o r moving t h e pump amounts t o 1 0 p e r c e n t of t h e t o t a l o p e r a t i n g time f o r t h e v e h i c l e .

A l t . I Crew: One man w i t h powered a u g e r , trnro men o p e r a t e f o u r pumps.

A l t - I1 Crew: One man w i t h powered a u g e r , two men o p e r a t e *TO pumps-

The following hourly c o s t s f o r machines and men a r e assumed: Rex

-

$2.00, towing v e h i c l e

-

$4.50

Typhon

-

$1.30, powered auger

-

$1.30 and t h e men $1.90.

mis

g i v e s t h e h o u r l y c o s t s presented i n Table 111.

TABLE I11

APPROXIMATE COST COR'IPARISON BET\VEEN

THE

RM

_{AND THE TYl?HON PTJMPS}

These r e s u l t s show t h a t f l o o d i n g with t h e Typhon auger and pump can be done a t about one-third t o one-half o f

t h e c o s t ( p e r flooded a r e a ) f o r t h e Rex pump. A comparison of t h e f l o o d i n g a b i l i t y between t h e London and Homelite pumps and t h e Typhon s e t , t a k i n g i n t o c o n s i d e r a t i o n t h e crews and a s s o c i a t e d equipment r e q u i r e d f o r t h e i r o p e r a t i o n , i n d i c a t e s t h a t t h e c o s t d i f f e r e n c e i s almost t h e same a s f o r t h e Rex and t h e Typhon.

I n conclusion it was found t h a t t h e s e t of powered auger and l i g h t screw pump was s u p e r i o r t o t h e equipment with which it was compared, with r e s p e c t t o t h e o p e r a t i n g c o s t s Per flooded a r e a and convenience i n handling.

Cost For pump For towing v e h i c l e For auger For men T o t a l c o s t s $/hr - - . -- At I r o q u o i s F a l l s , only a small p o r t i o n of t h e i c e

is prepared by flooding. The u s u a l technique of

co"sbXcti0n is t o compact t h e snow with r o l l e r s . _Since cheaper and more e f f e c t i v e equi3ment f o r f l o o d i n g i s non

a

-*

nAy--wG-m- p=-zL g u e s t i o n a r i s e s whether it would be p r a c t i c a l

--- - - Typhon A l t . I 1 - 3 0

-

0. 33 1.43 3.06 Rex A l t . I1 1. 30

-

0.65 2.85 4.80 A l t . I 2.00 4.50

-

3.80 10.30 A l t . I1 2.00 0.45

-

3.80 6.25

f o r t h e I r o q u o i s F a l l s a r e a t o f l o o d a l a r g e r p a r t of t h e l a n d i n g o r even t o f l o o d only and not compact. Factors t o be considered i n t h i s d e c i s i o n a r e discussed i n t h e f o l l o w i n g paragraphs.

I n Sweden, f o r a r e a s where t h e monthly snowfall i s

1 5

t o 25 i n . , it i s o f t e n necessary t o f l o o d a g a i n t h e same a r e a w i t h i n approximately f o u r days i n o r d e r t o avoid g r e a t

snow depths. A t Iroquois F a l l s t h e average snowfall i n December i s about 20 i n . If a three-day cycle i s used, one can expect an average depth of 2 i n . of new snon on t h e i c e f o r each flooding. According t o Swedish s t u d i e s ( I ) , a production of

5.5

a c r e s p e r 8-hr s h i f t with t h e l i g h t w e i g h t pump, can be expected i n t h i s snow depth. The h o u r l y c o s t would be about $3.10 (Table 111). This g i v e s $4.50 p e r a c r e f o r each s i n g l e flooding.

A t Iroquois F a l l s , when t h e i c e i s t h i n , compaction

i s done w i t h t h e small and medium-size r o l l e r s . A s soon a s c o n d i t i o n s allow ( i . e . , when t h e i c e t h i c k n e s s exceeds 12 i n . ) a b i g r o l l e r i s normally used. The production with t h e D4

and t h e b i g r o l l e r i s about 10 a c r e s p e r h r , and t h e h o u r l y c o s t $6.40 ( t h e c o s t of t h e r o l l e r s i s n o t t a k e n i n t o con- s i d e r a t i o n ) . If t h i s production and hourly c o s t i s r e resen- t a t i v e of t h e small and medium r o l l e r a l s o , a c o s t of $0.64 per a c r e each time compaction i s c a r r i e d o u t , i s obtained.

A common r u l e of thumb i s t h a t t h e i n c r e a s e i n i c e t h i c k n e s s per f l o o d i n g i s about 4 i n . I f t h e i n i t i a l i n t h i c k n e s s i s 4 i n . it would probably r e q u i r e 4 f l o o d i n g s and two weeks time t o i n c r e a s e t h i s t h i c k n e s s t o 20 i n . The t o t a l c o s t would be about $18.00 p e r a c r e .

According t o t h e experience of t h e A b i t i b i Co. a t Iroquois F a l l s , i f compaction i s used it w i l l t a k e about f o u r weeks and an average of e i g h t compactions t o o b t a i n 20 i n . of

i c e . This p r a c t i c a l experience was confirmed by c a l c u l a t i o n s using meteorological observations made a t I r o q u o i s F a l l s and a v a i l a b l e t a b l e s on i c e growth under d i f f e r e n t weather con- d i t i o n s . It was assumed t h a t t h e snow on t h e l a n d i n g was kept r o l l e d and t h a t a new snowfall was compacted s h o r t l y a f t e r it occurred. According t o t h e c o s t f i g u r e s given above, e i g h t compactions would c o s t about $5.00 p e r a c r e .

The above c a l c u l a t i o n s a r e approximate and a r e based on average c o n d i t i o n s f o r t h e I r o q u o i s F a l l s a r e a . They should hov~ever, give a reasonable comparison, f o r a r e a s of s i m i l a r c l i m a t e , of t h e d i r e c t o p e r a t i n g c o s t s f o r f l o o d i n g w i t h t h a t f o r compaction. Other f a c t o r s should a l s o be considered i n t h e comparison between f l o o d i n g and compaction, e. g.:

( a ) The r e l a t i v e q u a l i t y of t h e i c e obtained by t h e b.vo methods.

( b ) The r a t e a t which t h e i c e t h i c b e s s i s increased.

Flooding g e n e r a l l y produces t h e same t h i c k n e s s of i c e a s compaction in one-half o r l e s s t h e time.

( c ) Some of t h e snow i s transformed i n t o i c e by f l o o d i n g and t h i s can reduce maintenance c o s t s , s i n c e t h e r e i s l e s s snow t h a t has t o be ploughed o r t h a t can cause undesired f l o o d i n g of t h e l a n d i n e due t o a n overload of snow on t h e i c e .

The w r i t e r has r e f r a i n e d from g i v i n g a d e t a i l e d d i s c u s s i o n of t h e above f a c t o r s because t h e weight given t o each f o r a p a r t i c u l a r s i t u a t i o n depends on t h e l o c a l c o n d i t i o n s and t h e requirements t h a t t h e landing must f u l f i l . I t should be s t r e s s e d , however, t h a t t h e comparison between compaction and f l o o d i n g c a r r i e d out above, must not be generalized. The e f f i c i e n c y of t h e equipment and techniques f o r compaction discussed here a r e w e l l above t h e average f o r Eastern Canada. The c l i m a t i c c o n d i t i o n s i n t h e I r o q u o i s F a l l s a r e a a r e a l s o more favourable f o r t h e compaction a l t e r n a t i v e t h a n i n many o t h e r p l a c e s i n Ehstern Canada. I n t h e Lake S t . John a r e a , f o r example, compaction cannot be considered an acceptable method of preparing i c e landings f o r t r u c k s , because of frequent snowfalls and h i g h e r temperatures.

REFERENCES

1. Ager, B. H: son. Snow roads and i c e landings. Pulp and Paper Magazine of Canada, Woodlands S e c t i o n , J u l y 1961 (Technical Paper No. 127, Division of Building Research, National Research Council, Ottawa, 1961) 2. I n t e r n a t i o n a l C l a s s i f i c a t i o n f o r Snow, prepared by Schaefer,

V. J., G. J. Klein and M. R. de Quervain, f o r t h e Commission on Snow and I c e of t h e I n t e r n a t i o n a l

Association on Hydrology, I.U.G.G. (National Research Council, Associate Committee on S o i l and Snow Mechanics, Technical Memorandum No. 31, Ottawa, 1954)

Figure 1 The d i f f e r e n t types of conventional r o l l e r s

LEGEND

O _{LARGE ROLLER VIBRATING COMPACTOR}

0 MEDIUM ROLLER o VIB. COMPACTOR NOT

SMALL ROLLER V l B R A T l NG

N U M B E R OF PASSES

-+

S H E A R S T R E N G T H

FIGURE

3

COMPARISON OF DENSITY AND STRENGTH FOR

STRIPs COMPACTED WITH DIFFERENT EQUIPMENT

!

L E G E N D :

E

O LARGE ROLLER

r VIBRATING COMPACTOR

VIE. COMPACTOR NOT VIBRATING

SPEED MILES PER HOUR

---+

_{SHEAR STRENGTH}

16

-

(

RELATIVE VALUES) RAM HARDNESS

-

13 Y 100 1 14 E

-

₁₂

-

_{2 0 0} 0 W 13 0 - _{I I} a3

z

12 J CK 10 _1. 0 Z I- II

-

-

_{I 5 0}

₅

9 60 E l 0 - - 5 0 rn

_-

$ 9 - 13

-

8 100 a 0 1 2 3 4 5 6 0 1 2 3 4 5 6

F I G U R E 4

DEPENDENCE OF DENSITY AND S T R E N G T H

APF'ETirDIX A

TIME STUDIES ON ICE DRILLIBG AND FLOODING

1. D r i l l i n g w i t h t h e Typhon Auger. One man. The a u g e r was c a r r i e d between h o l e s .

( a ) 44 i n . of compacted snow on 25 i n . of b l u e i c e ; 1 0 0 - f t d i s t a n c e between t h e h o l e s .

( b ) 8 i n . of v i r g i n w i n d - d r i f t e d snow on 1 5 i n . of i c e , white and b l u e i c e ; 6 6 - f t d i s t a n c e between t h e h o l e s .

S t a r t Walking D r i l l i n g

Remarks: The c u t t i n g edges of t h e a u g e r were v e r y d u l l . I n good c o n d i t i o n t h e a u g e r h a s a d r i l l i n g speed of more t h a n

2 i n . p e r s e c . 1 3

-

18 1 9 1 7 1 7 1 7 135 ,128 60 88 56 72 S t a r t Walking D r i l l i n g

2. Handling

-

t h e Typhon Pump when Flooding. During t h e s t u d y , f l o o d i n g was c a r r i e d o u t f o r 4 t o 7 s e c only. _{One man} handled t h e pump. _{The pump was t r a n s p o r t e d qn t h e s l e i g h .} The engine was normally s t a r t e d o n l y once and l e f t running when n o t pumping.

(a) See above.

Sum 88 539 12

-

1 5 18 1 9 1 9 1 9 1 4 16 15 39 45 1 9 Average s e c 18 90 Sum 90 1 4 8 S t a r t Walking C l e a r i n g h o l e Take down Flooding Set-up Average s e c 18 25 32 4

-

23 1 9 1 9 1 7 1 7 25 24 2 1 20 20 19 - 1 2 7 7 6 ₇ 6 4 4 7 7 6 3 4 1 5 1 2 1 0 1 0 18 22 Sum 95 129 39 86 Average s e c 1 9 22 8 ( 6

1 5

A - 2 ( b ) See above. S t a r t Walking Clearing hole Placing pump Flooding ~emoving pump 18 0

17

21 28 21 24 10 11 8 8 11 11 5 6 6 8 9 6 4 0 5 0 5 6 7 6 2 6 11 9

1 5 1 4

9 12 Sum 111 59 70 Average s e c 22 10

7

( 5 )

1 4