Understanding Log Dimensions in Different Countries (Part 2)

Yesterday, we introduced some common measurement methods used in various countries around the world, especially those that are exported to China (click to view). Today, we will continue the previous article and introduce other measurement methods.

6) Hoppus Ruler

Created in 1736, it is said to be the earliest log measuring method still in use today.

Commonly found in Myanmar and India, such as Indian teak logs

To do this: Measure the girth of the log in the middle. Divide by 4 to get the mid-quarter girth. Imagine this number as the side length of a rectangular block and calculate its volume (square this number and multiply by the length).

Similar to North American boards, there is a concept of Hoppus foot (Hft), and the conversion relationship is as follows:

1HFT=0.036064m3=1.273 cubic feet

7) Doyle Ruler

Commonly used for American hardwood

The principle is to imagine a log of diameter D being turned into a cube with side length D-4, calculate the volume and then remove 25% of the saw path damage. So the formula is:

(D-4)² x L x 0.75/12 (D is the diameter in inches, L is the mill feet)

8) International Ruler Method

A method for measuring American hardwoods, developed by a brilliant thinker named Judson Clark, is said to be the most accurate method for calculating the actual yield of logs because it takes into account the approximately 1/2" increase in log diameter for every 4 feet and the approximately 1/8" cut in the lumber kerf. The formula then leads to a surprising result:

Unfortunately, this criterion is rarely used in practice.

9) Weight measurement method

Perhaps to save time, or perhaps because the value of the logs isn't worth the effort of manually measuring each one, the bulk measurement method works by measuring the number of cubic meters of logs under a certain weight (e.g., 10 truckloads of net weight) and using this average to calculate the volume of a larger number of logs (e.g., 100 truckloads). This method is commonly used for North American softwood, small-diameter lumber, and pulpwood.

10) Bundle inspection method

After stacking or loading the logs into containers, measure the length, width and height of the entire stack/bundle and multiply it by the density factor of 0.6.

This is often seen when logs are of low value or have been affected by natural disasters (such as strong winds, forest fires, insect infestations, etc.) and need to be sold quickly. This method of measurement is relatively crude, and buyers can often get a considerable markup.

In summary, due to the different histories and traditions of different regions of the world, the measurement methods of logs vary, and sometimes even vary greatly. When importing logs, you must first understand the measurement method on which the quotation of logs is based.