Teaching Tension & Compression

I recently had a student that found it difficult to fully grasp the concept of tension and compression wood. This student understood that if a piece of timber was only held at one end, then the compression wood was underneath, and that's where the first cut would be made; but when it was balanced at either end, they just couldn't see it. What I needed was a way to help this student understand where the cut should be made - this gained particular significance as I'd been told that they had failed a previous attempt at CS30 on demonstrating knowledge of tension and compression! Find out my solution after the jump...

After we had been down the woodyard, practicing the crosscutting, I have to admit that I thought we'd got it sussed. But we hadn't - my fault really and now I needed to come up with something that would help this student. Walking back, I was running various ideas through my head when I had a moment of inspiration.

I needed something quick, simple and easy to understand. Perhaps something this student could take away with them to practice with.

The result can be seen in the picture at the top of this post - click on it to get it full size (A4). Here's how it works...

• Cut out around the edge of the rectangles, and then fold in half as it shows.


• After folding it, glue it together just to hold the halves in place.


• The elliptical pads represent where the wood is held up - so if you place the single pad touching on a table, or whatever, with the other end free, you'll see that the free end sags down (because there's nothing holding it up). Holding it this way, you can also see that the letter 'T' (tension) is uppermost and the number '2' (second cut) is showing. This tells you that the compression wood, which you would cut into first, is on the underside of the timber.


• Now turn the paper over and balance the two pads at either end across your hands. You can now see that the letter 'C' (compression) is on top, and the number '1' (first cut) is showing. This tells you that the first cut to make is the compression wood on top.

It's easier to do, than to explain ;-)

Anyway, if it's of use to anyone, then please feel free to download it and give it a go. If you're a trainer, then feel free to use it. As for my student? They passed with flying colours.

Supporting Dyslexic Learners

This year I've been much more aware of many learners attending my courses who are dyslexic - whether they have mild 'symptoms' or serious dyslexia and find it extremely difficult to read at all. Whilst the NPTC assessments are practical based, with questions asked to test knowledge, the problem still remains for trainers to put across information in a manner suitable for everyone, irrespective of any learning difficulties.

This is an area that I'm just starting to learn about myself, and over the last 6-9 months I've been trying to help those that are dyslexic so that they can revise skills and knowledge learnt on a course. Find out more after the jump...

Here at Sparsholt College, at the start of the year I tweaked the application process so that I knew in advance if learners with learning difficulties, dyslexia and so on, were to attend a course. This sort of knowledge is important to a trainer so that we can make our lessons inclusive for everyone.

For starters, I rely heavily on imagery when I teach, although I can't get away entirely from text here and there; and of course the course notes that every student gets have large areas of text. From what I've learnt, the colour of the paper that the notes are written on can make a big impact, improving readability. I now make it a point to ask any students if they would prefer to have their notes printed on something other than standard white paper.

It's only a small thing, but the response from dyslexic students has been interesting - it really seems to make a difference. In fact, one student was really taken by the fact that I had asked and made a comment along the lines of "Thanks, yes I'd like it on pale yellow paper. I can't believe you care - where I was before just treated me as if I was stupid". That's no way to treat anyone and I;ve had other students who have benefited from this small change.

It's also why I have introduced some audio stuff here on DriveLink, as well as video. It's just another way of getting across the information, some will prefer to watch a video, others will hate it. That's fine - as long as they get the skills and knowledge they need to operate a chainsaw, fell a tree, or climb, safely.

The image at the top of the screen was actually destined to be a storyboard for another instructional video that I want to make (I've got so many ideas for videos!), but I also wondered of it was useful to others as a quick reference on how to sharpen a chain. Naturally, it's a bit light on actual information (that's what the video will be for), but as an aide-memoire or quick reference, if it's useful to someone then print it off. It's sized for A4 paper, so should just print out fine.

If you're reading this, and you've got staff, or you know someone that has learning difficulties of some sort, then make sure they get the training they deserve - improving the effectiveness of the training we deliver will help reduce accidents and increase knowledge across this industry.

- David -