by James Shand, Know Tech Envirtonmental Inc.

If there is anything a live-lobster shipping company wants, it is to ensure that the quality and reliability of its products and services are better than that of their competitors. When companies are faced with shorter delivery times, coupled with high distribution levels, it means that they may need to rely on machinery to not only meet the demands of their customers but also to be able to optimize efficiency to the point that they can remain competitive.

Lobster grading is the process by which lobsters are evaluated for the quality criteria critical to successfully retaining existing customers and recruiting new ones. In the live lobster business customers expect that lobsters received will arrive when promised, be alive and in good, undamaged condition, and in the size range ordered. Penalties are imposed when dead or weak lobsters are received. Boat-run lobsters are sorted into two classes: (1) Class A – perfectly formed (two claws, no deformities) hard shelled specimens and (2) Class B – culls, specimens that have one or no claws, are malformed, are damaged or bleeding, or are less than hard-shelled. In addition, grading includes separating the “Class A” lobsters into standard weight classes as in Table 1. Certain customers may require customized weight ranges.

The first part of the grading process (removing the culls) requires trained workers. The second part (sorting the lobsters into weight classes, accurately) is done manually or by partially or fully automated means using accurate digital scales. Lobsters are stressed by handling. Lobsters can be damaged by rough handling during the grading process. A dead lobster must be discarded – it cannot be salvaged. Thus, it is very important that a high level of care is exercised when handling lobsters.

Low volume manual sorting

The sorting process for small batches of lobsters can be performed by one worker weighing each lobster individually on a digital scale and placing it in the appropriate destination crate. It is a slow and tedious job.

Medium volume manual sorting

For higher volumes, the traditional method involves two workers and a digital scale. One person removes a lobster from the supply crate and places it on the digital scale. The other person reads the weight on the digital indicator, removes the lobster from the scale and places it in one of several destination crates, depending on the weight of the lobster. About 1,000 lb per hour (10 crates) can be produced using this method. There are several problems with this approach. Two workers are needed per scale. The work is repetitive and boring. Each lobster is handled twice. During periods of high volume, workers become exhausted, slow down and begin to make sorting errors, and may start being careless about handling, causing injuries to the lobsters. For the company, quality suffers and losses mount.

Medium to high volume sorted by partial automation

The next level of productivity improvement involves partial automation. Using a “reverse weighing scale” one worker can grade lobsters almost as fast as two workers using the traditional approach. With the reverse weighing, a crate of lobsters is placed on the digital scale. Only one operator is required. As each non-cull lobster is removed from the supply crate, based on the change in weight, the digital indicator shows which destination crate the lobster should be placed in. The operator observes the readout and places the lobster in the correct crate. Although reverse weighing scales are relatively expensive, if available (google does not show anything), they do facilitate a 50 % improvement in labour productivity. One worker can produce 10 crates of graded lobsters per hour.

This is where the Know Tech VisiGrader fits in. It transforms most digital scales into “reverse weighing” scales. The VisiGrader consists of 7 inch touchscreen in a waterproof box which is connected to the digital scale indicator and is mounted nearby, in sight of the operator. As each lobster is removed from the supply crate, the VisiGrader instantly indicates by color and crate number on the screen, the destination crate the lobster should be placed in. The person grading simply observes the color or crate number and places the lobster in the correct crate.

This cuts labour costs by half, compared to the traditional method. Each destination crate is assigned a weight range. The operator is not concerned with the weight of the individual lobster – knowing the crate to put it in is enough. As soon as the operator is trained to select Class A lobsters and discard the Class B culls, he or she can begin to grade lobsters for both quality and weight. This is a much simpler job than reading a numeric weight and then mentally calculating which crate to put the lobster in. It is much less fatiguing for the operator.

Live lobster companies find that using partial automation, such as the VisiGrader, offers the following benefits:

• improved grading accuracy,

• easier for new workers to learn how to grade lobsters more quickly,

• reduced labour costs,

• reduced lobster stress and mortality

• reduced worker stress

• reduced lobster hidden damage and injuries

• retains the robust quality of hand sorted lobsters

Fully automatic machine sorting

With fully automated sorting systems, one or more workers are required to divide the catch into Class A and Class B categories. Then the Clsss A lobsters are fed into the automatic grader via a conveyor belt. As the lobsters travel along the belt each one is weighed by an electronic scale. Depending of the weight of each lobster, it is steered off the conveyor belt by a gate appropriate for the weight of the lobster. It then slides or falls into a crate or other container reserved for the weight range that the lobster happens to belong to. Workers are standing by to remove the destination crates as they become full and to keep the quality grading workers supplied with crates of boat-run lobsters to be graded. A crew of 8 or 9 workers is required to keep pace with an automatic weight sorter.

Automated sorting systems for lobsters have an essential role to play in making sure live lobsters are accurately sorted and are undamaged in the process. Lobster companies understand the accuracy, capacity and speed benefits that an automated sorting machine can bring to a production line

Here are a few concrete advantages of both fully and partially automatic sorting machines.

Increased efficiency

Increased efficiency starts with the employees working on the floor. Automated sorting machines can consistently do the same repetitive procedures to a high standard, which then lowers the occurrence of injuries or worse, accidents. When accidents that cause injuries happen, they can result in the affected party having to take the time off, which then raises production or operation costs for lobster company.

The benefit for workers is the chance to improve their skills in the company, moving away from uninspiring roles which require them to go through the same motions over and over again. An automated sorting system does not need to take breaks, neither do they need time off. Additionally, they are able to process a larger volume of lobsters in a shorter amount of time.

 Reduced costs

When this is combined with an increased throughput rate, reduced costs can offer massive benefits for businesses. The upfront costs associated with purchasing any piece of automation has to be assessed by a business before any financial commitment is made. This means that it should also be tempered with the associated return on investment. The great thing about an automated lobster sorting machine is the fact that the gain or return on investment process is not slow, the efficiency gains are nearly instantaneous, meaning that savings will impact the bottom line right away.

Improved accuracy

In numerous sectors all over the world, accuracy is perhaps the most important factor. Sorting machines have to operate not only quickly but, in a cost effective manner, whilst ensuring there is never a compromise in quality.

Human error typically plays a significant role in a number of less than accurate incidents that happen in a facility, especially a lobster sorting facility. With the introduction of automated sorting systems, the majority of these concerns are removed. The positive benefit is that operations then become held to a consistently higher standard, which could then increase the visibility of an organization, bringing in new customers.

Numerous benefits such as a faster-operating speed, increased safety for workers, improved quality and reduced costs are why businesses should consider automatic sorting machines.

Fully automatic sorting systems also have some disadvantages.

System Costs

The cost of an automatic sorting system is about 20 times the cost of a single, partially automated grading station (such as the VisiGrader). Companies using automatic graders must handle large quantities of lobster in order to justify the investment. Breakdowns are costly because the time to repair and/or adjust an automatic sorting system requires a higher level of expertise that may not be readily available – delaying the recovery and increasing the cost of the reduction in output.

Hidden lobster damage

One of the main disadvantages of an automatic grader is that the mechanical apparatus often inflicts hidden damage upon the lobsters. This may result in customers receiving more dead or weak lobsters if they are held in storage very long or are otherwise-delayed in getting to market. Customers will not pay for dead and/or weak lobsters and the reputation of the supplier is negatively affected.

Reduced lobster volume

Another problem becomes evident when lobster volumes drop and only relatively small batches of lobsters require grading. Depending on the company, there may be rules regarding the minimum period that employees have to be paid for if they are called in. For example, it is a rule in some companies that employees must be paid for 3 hours of work if they are called in. Because of the large crew size required to operate the grader and grading a small batch will only require a short period of time, losses may result if there is no additional work for the called in employees to do. The alternative is to delay processing the small batches, resulting in losses due to increased dead and/or weak lobsters. Thus, companies that are using automatic graders may find it beneficial to acquire one or two partially automated grading stations to more quickly process small batches.

Summary

Efficient and effective lobster grading is a critical success factor in the live lobster business. Moving from manual grading to partially automated grading can help companies increase their productivity while maintaining their reputation for quality. The annual rate of return on money invested in reverse grading equipment, such as the VisiGrader, can exceed 100 % on sales volumes as low as 3,000 crates per year.