Wooden cars

You might have seen the picture of the Japanese wooden electric car in today's Metro newspaper. Not so stylish you are probably thinking, but some people really like to have a car made from wood - like this man from Ukraine.



Well, perhaps that is also a bit too much for most people's tastes. ...but how about cruising around town in one of these...



If you keep your eyes peeled you might still spot an iconic Morris Minor Traveller on a UK road...or one of the wooden framed Morgan sports cars.

You might be thinking the days of wood for making car bodies are long gone, but you could be very wrong. There is a lot of research going on into natural composite materials that use plant fibres and chemicals (including wood) to make materials that have high performance but also better environmental credentials.

The chemistry of wood

This video is all about the chemistry of wood - and contains a lot of cutting edge science. The structures in wood that help determine its properties are tiny - it its only recently that technology has developed to the point were we can measure them and work out what they do. The work means chemists, engineers and foresters working together. This video is also available on the firrs DVD.



Here's another short wood science video that mentions cellulose and lignin - this one is from the History Channel.

What is civil engineering?

Not many people know much about civil engineers and what they do. They might know that they build bridges and tall buildings but they rarely appreciate exactly how much our lives - and civilisation itself - depends on civil engineering. Much of it we think about - either because we can't see it, or because it works so well we take it for granted.

At the most basic level civil engineering is about providing people with clean water, shelter and sanitation. These things are fundamental to human life and arguably civil engineers have saved more lives than the medical profession.

...but it's more than just that. Civil engineering covers a huge array of disciplines as this video from the Institution of Civil Engineers shows.



You might be thinking, "but what has this got to do with timber?" Well quite a lot as it happens. Timber is one of the few renewable building materials and it becoming increasingly important for larger construction projects as well as for building homes. For this reason, civil engineering degrees are now more likely to include timber as well as steel and concrete (especially the courses we run at Napier). But civil engineering is also needed to create and maintain forests, to prepare the ground, ensure the right amount of water in the soil, and to provide access roads and bridges. In fact, if you've not watched the firrs DVD, you might be surprised to learn that the Forestry Commission employs civil engineers.

Interactive physics (Phun)

There are a few interactive physics games out there, but this one is really excellent. You can read about it and download a beta version of the software at http://www.phun.at/. You can build all sorts of machines and structures.

why wood : what wood

Last week I gave a presentation it the Institute of Materials, Minerals and Mining in London, which was part of their Materials and Design Exchange (MADE). This was intended as an introduction to wood as a material and used some of the videos made for the firrs project. You can download a pdf copy of my presentation, with a few notes on what I said, here.

Anaglyph for 3D video

Anaglyph is the technical name for a technique of making images that have a stereoscopic 3D effect - so rather than appearing flat like a picture they appear to have depth like objects in the real world.

The anaglyph technique uses glasses with coloured filters to make it so that each eye sees a slightly different view. You can read up on how they work and how to make them yourself on Wikipedia. It's actually quite easy with modern technology, but the technique is quite an old one.

There are applications outside entertainment, and anaglyphs can be used help visualisation in science and design. Examples include viewing microscope images and models of chemicals. You can see some anaglyph photographs in the 3D gallery on the firrs webpage.

This video is mainly a bit of fun, but it shows how the anaglyph technique can be used in moving images. You can watch a much higher quality version here.

Is it wood, is it bricks or is it lego?

Time to practice your French with this post. One of the big new things coming over from continental Europe is "massive wood construction". This is an extension of the idea of a traditional log cabin - in which the walls are solid wood - but updated with modern hi-tech manufacturing methods. So instead of irregular round logs you have nice regular building blocks.

This provides very good insulation keeping the heat in and the noise from outside out. It's also greener than conventional fired clay bricks - which require more energy to make and produce more carbon dioxide in the process.

Obviously it requires an awful lot of wood, but the good thing is that cheaper, low quality, wood can be used. As there is so much of it, the force is shared over a bigger area, meaning it doesn't have to be nearly as strong or as stiff as the wood used in a timber frame building.

You might see this type of construction more often in the next few years for buildings like schools and hotels.

The first video is an explanation (in French) of one particular system of massive wood construction (there are others). Notice the computer controlled robotic cutting and drilling machines. Wood manufacturing really is like this in the 21st century.

The second video, which has no sound, shows the same system being used to actually construct a building. Notice how accurately the pieces fit together thanks to the precision manufacturing.

Social science

As well as the natural sciences, like biology, chemistry and physics, forestry involves the social sciences - the study of human behaviour and society. Forests provide many important benefits to people and communities.

Social forestry is the study of things like:

• How people interact with forests
• How foresters can improve engagement with local communities
• How forests support employment and rural economies
• How forests contribute to health and wellbeing

As a public body, the Forestry Commission has been particularly active in this area, but private forestry companies also make use of social forestry.

Forestry, timber and climate change

Forests and climate change are very closely linked, but in ways that are not generally well understood by the public. The science is complex and interconnected and often you hear only one side of the story. Fortunately the Forestry Commission has recently released a video that covers the subject in a very clear and balanced way. It also tackles a few widely believed myths too. I challenge you to watch it and see if it doesn't tell you something that surprises you.

The reality is that human impact on forests is both a problem and a solution - and that we need science to tell us what the consequences of our actions are. If you are thinking of a science or engineering based career that helps save the planet you couldn't do much better than working in the forestry and timber.

Forests are vast sinks of the greenhouse gas CO2 but they offer so much more - from renewable energy to low carbon building materials...just so long as they are sustainably managed. The challenge for foresters is to use science to understand both the effect of forestry on climate change ...and the effect of climate change on forestry.

You can download a high quality copy of the video at the Forestry Commission's website: http://www.forestry.gov.uk/forestry/INFD-6umkar

Christmas trees

It's December so a good time talk about science of Christmas trees.

Apart from looking and smelling wonderful, real trees use fewer materials and less energy to grow than artificial trees take to make...and if you recycle the tree afterwards (which you should) it can be turned into useful compost.

There are three main groups of plants that produce woody material:

1. Softwoods like pine and spruce
2. Hardwoods like oak and ash
3. And woody monocots like bamboo and palm

This classification is botanical and has nothing to do with the hardness of the wood material (or any other mechanical property). Unless you're going to be particularly unusual this year, you'll be wanting a softwood as your Christmas tree...a cone shaped tree with needles.

Trees can be known by a common name and by a scientific name.

Common names differ around the world – even between English speaking countries. For example, the timbers known as redwood in North America (chiefly sequoia) are not the same as the timber known as redwood in Europe (Scots pine). This is why it is useful to use scientific (botanical) names in addition to the common name to avoid potential confusion.

Botanical names have two parts. The first word denotes the genus (family) and the second word denotes the species. The name is normally written in italics.

So types of wood that have the same genus name (e.g. Picea sitchensis and Picea abies) can be seen to belong to the same family...in this case spruces (Sitka spruce and Norway spruce).

These days there are lots of different species of christmas tree to choose from. Here are a few examples...

Norway Spruce (Picea abies) is the traditional Christmas tree in the UK. It has a mid-green colour, a fine delicate foliage and a rich Christmassy scent. While fine in the chilly halls of Victorian times, it tends to drop its needles in modern centrally heated houses. Although we call it Norway Spruce the tree is native to a wide area including central and southern Europe, southern Scandinavia and the Balkans. This is also an important timber tree for the UK and is used to make timber framed houses. Mature trees grow about 35-50 metres tall.

Scots Pine (Pinus sylvestris) is the traditional North American Christmas tree. It has the advantage that it keeps its needles well so long as you keep the tree from drying out. The downside is that the needles are pin sharp. If you like your tree to be more tree than decorations this is a good one to go for as it tends to have lots of tightly packed branches. Scots pine is certainly not limited to Scotland...it has the widest natural range of any pine, growing right across northern Europe and Asia. This is also an important timber tree for the UK and is used to make timber framed houses. Mature trees grow about 25 to 35 metres tall.

Lodgepole Pine (Pinus contorta) has a cheerful yellowish green colour, and a sharp fragrance. It is native to the Rocky Mountains in North America and was introduced into the UK in 1855 because growers liked its ability to grow well on poor wet soils and its resistance to pests.

Korean Fir (Abies koreana) is a tree native to Korea that was introduced into the UK in 1913. Mature trees are relatively small, growing only about 10 metres in height. It has a bright silver undersides to the leaves, white buds and grows tightly packed branches making it an attractive choice.

Virtual forest tour

UPM's Forest Life is a really beautiful combination of Flash, still photography, video and audio. It takes you on a tour of a Finnish forest looking at trees, plants, animals and people. Find out about how forests are managed sustainably for different purposes and how there is much more to a forest than just the trees.

The science of sound

Here we have a couple more films from the Prelinger Archive. The first from 1933 and the second made in 1948...back when a scrap of wood on a piece of string was carried by every child.

These videos explain the science of sound...what it is and how it's made. This will help you understand our video "measuring stiffness with sound".

Careers in the timber industry

The UK's multipurpose forests provide environmentally friendly materials for all sorts of things and there are a vast array of different types of job out there.

For more information on jobs visit The Doorway and A Job In.

Chainsaw impersonation

Unbelievable but real...the Australian lyre bird can sing like a forester.

National tree week

"National tree week" starts today and runs until the 2nd of December. The Tree Council has organised several events around the UK celebrating trees and planting new ones.

If you want to know how to identify some of the trees that grow in the UK from their leaves you can play Kerf's leaf quiz on the main firrs website. There are more identification guides over at the Woodland Trust's Nature Detectives.

Tree planting is a great team building and feelgood activity to do in schools...and it goes on all over the world. This is a video made by a school in Costa Rica.



Trees can be planted as seeds, as small saplings, or as young trees several metres tall. Remember, although larger trees give instant satisfaction they also weigh more. It's also good to have a bit of expert advice to make sure the trees thrive and you know how to look after them.

You can still join in even if you don't have much outdoor space ....you can plant a tree as a bonsai.

Deforestation and certification

This video from Greenpeace has a forceful message. It asks the question:

"Why destroy ancient forests for wood and paper, when it can all come from responsibly logged timber?"

Why indeed.

Well one reason this happens is that many people don't really understand how they can choose wood products that are environmentally sustainable - and come from properly managed forests. There is good wood and bad wood and we all need to understand the difference. Check out the certification schemes like FSC and look for the logos. Buying certified wood is a good thing...it encourages people to look after their forests.

Measuring stiffness with sound

It is very useful to know the engineering properties of the timber in logs before they are sent to the sawmill. Time and energy spent sawing up a log and kiln drying the battens is wasted if that timber later fails to meet the grade for construction. It would be much better to put that log to another use.

The science of sound allows us to do just that. The speed of sound through any material is related to the material's stiffness. In fact, stiffness equals density times the speed of sound squared.

That means if we can measure the speed of sound and the density we can calculate stiffness.

To do this we measure how long it takes the sound to travel from one end of the piece of timber to the other. Then it’s simply a case of speed equals distance divided by time. To explore the science further why not look at our whack-a-stick simulation or read about our exhibit at the Royal Society Summer Science Fair 2007?



This was one of the first videos we made. Annie and Heraa had just started their Nuffield Science Bursaries and we were practicing using the video camera. It just so happened that on the day, Peter Carter from Fibregen was visiting the laboratory to talk about his acoustic testing tool with John and Andy from the SIRT project.

We decided it was a good opportunity to make a short video, so Annie and Heraa asked Peter how it worked and we videoed Annie doing a demonstration.

This tool, the HM200, is called the Director, but people also call it the "Hitman". It is designed to work in busy, noisy timber yards but in the quiet of your own home or classroom you can make your own "non-destructive acoustic testing device". All you need is a microphone and a computer with some software that will analyse the frequency of sound. We have found that the free software called Audacity can do this well enough for a demonstration.

When you hit the end of the wooden batten with a hammer, the main sound you can hear is the sound of the first mode of resonance. The frequency of the first mode of resonance is the time it takes the sound to travel along the batten, bounce off the end and travel back down the length of the batten. This means the wavelength of the first mode of resonance is twice the length of the batten.

It sounds complicated at first, but it’s actually quite simple. All you need to do is hit the piece of timber and analyse the sound to find out what frequency it was mainly made off. So long as everything is working as it should, that is your first mode frequency.

To calculate the speed of sound in the timber:

(Speed of sound) = (wavelength) x (frequency) = 2 x (batten length) x (frequency)

And to calculate stiffness:

(Stiffness) = (density) x (speed of sound) x (speed of sound)

Here is some proof that we did not fake anything for the video. We took the audio recorded from the video and opened it in Audacity (we've extracted the sound of the hammer strikes so you can do this yourself). We then selected the sound of the hammer strike and selected "plot spectrum" from the "analyze" menu.

What we want to look at is the frequency spectrum – that's the graph with frequency on the horizontal axis and the level on the vertical axis. The higher the level the more of that frequency there is in the sound.

The sound contains lots of different frequencies, but we are mainly interested in the highest peak. This is a frequency of 554 Hz.

And if we look at what the figure on the laptop in the video it says 558 Hz. Pretty close huh?



Did you notice the time on the laptop clock? We don't work that late! That was New Zealand time. The laptop was Peter's and that's where he lives.

Horses

Some of the UK's forests were created hundreds of years ago as places for the rich to ride their horses...and now anybody can do it.

There are several jobs involved in working with horses in the forest and maintaining the bridalways. For small tree harvesting operations and tree thinning it is often best to use the traditional methods of horse logging. Horse loggers can move up to 10 tonnes of timber in a day leaving hardly a trace, and making hardly a sound. The big shire horses work best on flat lowland forests, while forests with hills and steep banks require smaller, more agile, horses. Horses are also used to move materials and equipment and to control invasive weeds like brambles and bracken.

How trees are harvested

Think you know what a lumberjack is? A big guy with a beard, a checked shirt and an axe? Possibly saving girls in red hoods from wolves dressed as grandmothers? Well think again...

For starters the people (men and women) who take down the trees are called loggers or harvesters...and its all part of forest management, which also includes tree planting, silviculture, landscaping and a range of other 'forest operations'.

Technology has changed the job considerably from the days of yore. Chainsaws started to replace axes back in the 1920s, but these days most of the trees grown for timber in countries like the UK are felled by machines a bit like the ones you see on construction sites. These machines can cut a tree, strip the branches and cut the logs to length in a matter of seconds...plus they have a lot of other fancy gadgets too...like GPS to locate the trees marked for felling. Other types of specialised machines are used to get the logs to the road and on to the sawmills.

All this is done while causing minimum damage to the forest floor and to young trees. The forest owners don't want their future timber crops to be put at risk...or any income they get from other uses of the forests such as recreation and tourism.

In some areas the land is so inaccessible that other methods have to be used, such as horses and helicopters ...or even submarines and machines that walk on legs!

Reg Kehoe and his marimba queens

This one is a special treat...no educational content except the observation that marimbas are usually made of wood!

The bars for the lowest pitched notes are wider and longer, and gradually get thinner and shorter as the notes get higher.

Like the bars of a xylophone, the bars of a marimba are most commonly made from rosewood, but they can also be made from padouk and various synthetic materials.

Rosewood is the name given to a number of different timbers which have a rich dark red colour and a sweet smell. They are heavy and have strong resonance making them good for musical instruments. Unfortunately, many rosewoods, like Brazilian rosewood (Dalbergia nigra), are endangered due to over exploitation and should not be used.