Export and Domestic Scaling in New Zealand

SOME NZ FORESTRY FACTS

• 19.8 million m3 cut in 06/07• 6.3 million m3 logs exported• 1.87 million ha radiata pine• 2.1 million ha plantation

EXPORT SECTOR ERODED BY:

• High dollar (NZ$0.76 USD)• Freight rates (>$70/tonne)• Availability of shipping

Scaling methods in NZ

• Export logs scaled in JAS• Domestic logs weigh-scaled or sold in

tonnes• Voluntary standard

Japanese Agricultural Standard (JAS)

JASvolume

JASMeasurements

• Shortest small-end diameter through centre of sawn end

• Second diameter at right angles to first• Round down to even centimetre• < 14 each centimetre rounded down • Allow for end conditions

Fig. 7: Trumpet. Small-end diameter is reduced toexclude swelling.

Fig. 11: Small-end swelling with bark-encased knot. Thisdoes not affect measurement, but swelling and fluting

do.

Fig. 13: Small-end swelling with intergrown knot.Swellings are excluded from measurements.

Fig. 27: Broken end. Exclude broken piece because itextends more than 10 cm into the log.

Toll Owens volume variation on time

-5

-4

-3

-2

-1

0

1

2

3

4

5

Jun-

05

Jul-0

5

Aug

-05

Sep

-05

Oct

-05

Nov

-05

Dec

-05

Jan-

06

Feb-

06

Mar

-06

Apr-

06

May

-06

Jun-

06

Jul-0

6

Aug

-06

Sep

-06

Oct

-06

Nov

-06

Dec

-06

Jan-

07

Feb-

07

Mar

-07

Apr-

07

May

-07

Jun-

07

Jul-0

7

Date of checkscale

% d

iffer

ence

bet

wee

n ch

ksca

le a

nd o

rigin

al

required upperrequired lower Actual bias

Toll Owens

• 5.1 million m3 export logs• 13 sites• 95 scalers• 49 scaler/operators

Statistical QC System

• Check scalers at each location• Monthly random samples• Feedback to scalers• Each scaler monitored• 3 month calibration check

Accuracy criteria

• Volume bias within 3%• Scalers should agree on diameters of 62.5%

of small-ends• 95% of logs should be scaled within 2 cm

Volume variation Mount Maunganui

-6

-4

-2

0

2

4

6

Dec

-04

Jan-

05

Feb-

05

Mar

-05

Apr

-05

May

-05

Jun-

05

Jul-0

5

Aug

-05

Sep

-05

Oct

-05

Nov

-05

Dec

-05

Jan-

06

Feb-

06

Mar

-06

Apr

-06

May

-06

Jun-

06

Jul-0

6

Aug

-06

Sep

-06

Oct

-06

Nov

-06

Dec

-06

Jan-

07

Feb-

07

Mar

-07

Apr

-07

May

-07

Jun-

07

Jul-0

7

Aug

-07

Sep

-07

Date of checkscale

% d

iffer

ence

from

orig

inal

MountLower limitUpper limit

Scaling precision Mount Maunganui

30

40

50

60

70

80

90

Dec

-04

Jan-

05

Feb-

05

Mar

-05

Apr

-05

May

-05

Jun-

05

Jul-0

5

Aug

-05

Sep

-05

Oct

-05

Nov

-05

Dec

-05

Jan-

06

Feb-

06

Mar

-06

Apr

-06

May

-06

Jun-

06

Jul-0

6

Aug

-06

Sep

-06

Oct

-06

Nov

-06

Dec

-06

Jan-

07

Feb-

07

Mar

-07

Apr

-07

May

-07

Jun-

07

Jul-0

7

Aug

-07

Sep

-07

Date of checkscale

% lo

gs s

cale

d th

e sa

me

by c

heck

and

orig

inal

Mt Maung

Requiredprecision

3D Scaling

3 D Scaling

• Weigh scale samples• Valuable logs• Both end diameters and length

3D formulaVolume components of log

Domestic scaling

S.E.D.

Cylindrical volume

Peripheral (or taper)volume

Leng

th

3DMeasurements

• Shortest diameter through centre of both sawn ends

• Second diameter at right angles to first• Round to nearest centimetre• No reduction for butt flare• “Shortest” length to nearest centimetre

Domestic scaling requirements

• Done by a variety of contractors• Each scaler to sit “domestic “ scaling

module• Must scale 50 logs by the 3D scaling

method and be within 1% of assessors volume