Freight Seesaw
Download on the App Store Get it on Google Play

Q: How is the balance point related to axle weights?
A: Suppose you were to replace an entire truckload with an extremely dense golf ball that weighs exactly the same as what the truckload weighs and you place this golf ball at the truckload's balance point. According to the laws of physics, the axle weights for the golf ball will be exactly the same as they are for the truckload.

By the same token, any two truckloads that weigh the same will produce the same axle weights if they have the same balance point.

What Freight Seesaw essentially does is rank pallet patterns based on their theoretical nose-to-rear weight distributions. Given any two pallet patterns that do not have the same balance point, assuming all other things are equal Freight Seesaw tells you which one is heavier in the nose (and therefore lighter in the rear) than the other.
Q: Assuming the freight weighs the same, does the same balance point on Freight Seesaw always produce the same axle weights in the real world?
A: Not necessarily; in the same way that weather predictions can be wrong sometimes, so can Freight Seesaw. Both use mathematical models to make their predictions. The balance point of a pallet pattern is a mathematical model that predicts the actual balance point of a truckload, which in turn determines the loaded axle weights (given the empty axle weights).
Q: How does the percent column work?
A: To perform its calculation, Freight Seesaw disregards actual pallet weights. Instead, it just needs to know the percentage of the (user-selected) base weight that any given pallet weighs.

When all pallets weigh the same, the base weight is automatically the weight of any pallet in the load. In this scenario the percent column can be ignored since each pallet weighs 100 percent of the base weight.

When some pallets weigh more than others, a base weight must be selected. It is usually easiest to select the weight that appears most often.

For example suppose a truckload has the following pallet weights:

2000 pounds (18 pallets)
1800 pounds (2 pallets)
1600 pounds (2 pallets)

Clearly the easiest weight to use for the base weight in this scenario is 2000 pounds. Since 1800 is 90 percent of 2000, any row that consists entirely of 1800-pound pallets should have 90 in the percent column. For a row consisting of one 1600-pound pallet and one 2000-pound pallet, since 3600 is 90 percent of 4000, it is again correct to enter 90 in the percent column.

A calculator that converts pallet weights into percentages is available here.