Walls in the Willows - a renewable construction material

This week I was fascinated by a lunchtime talk about a renewable construction material that grows itself: retaining walls made from willow! This has been used in several locations in Norfolk either on its own (for footpaths or river banks which aren't particularly sensitive to settlement) or to provide living scour protection for gabion basket walls (for roads or rail applications).

Willow spiling wall comprises posts and withy infill.
Image from JPR Environmental

What is willow spiling?
A willow spiling wall consists of two elements:

• Live timber posts measuring at least 100mm in diameter (being a natural material, the size will vary somewhat) which are installed at 0.6 to 1.0m centres like a king post wall. 
• Willow "withies" are woven between the posts to form the infill panels (as this is a fairly open weave, a layer of Terram is advised on the landward side of the wall to prevent loss of fines). Backfill to the retaining wall should comprise silt, sand or gravel.

Wildlife Watching at St Nick's Field

One of the best ways to spend a sunny Saturday afternoon is nature-spotting, so I was pleased that there are regular opportunities to join organised wildlife-spotting walks at one of my favourite places: St Nick's Fields nature reserve in York. A few weeks ago, twenty of us enjoyed a pleasant walk with the help of expert volunteers who pointed out insects, plants and birds, including frequent stops to look at things more closely or get excited about something a little way off the path. 

The walk was at the start of the Big Butterfly Count, an annual fortnight-long initiative to record sightings of butterflies around the UK, and therefore understand the geographical spread and frequency of different species. Butterflies are particularly vulnerable to pollution and habitat loss, so make a useful marker for the health or otherwise of our natural world. 

Following the Yellow Train!

“Yellow Car” is a good way to keep children quiet on long journeys, as you score points if you’re the first person to shout whenever you spot one (and other than my friend Miles, there aren’t that many yellow cars on the road. I like playing a different version when I’m out on track, because spotting the yellow train is even more rare (there is only one which covers the whole country!)

So why is it painted yellow? This is Network Rail’s colour, chosen to look like no-one else’s livery and probably also because most of the “yellow plant” (rail-mounted kit for maintaining the track and wires) and engineering trains (essentially freight trains transporting ballast or track) need to be visible in the dark, because we rail engineers rarely have the luxury of being able to do construction work during the day!

But the yellow train I like to watch out for is an HST (that’s your average intercity-type passenger train to non-trainspotters) painted bright yellow and marked “New Measurement Train” on the side. This one train is a piece of technology that has revolutionised how we maintain the UK railway because it travels the whole passenger network over a regular cycle and measures the condition of the track and the overhead wires (are they in the right place and delivering the right amount of power?), saving thousands of hours of track inspection time. 

A Windy Wildlife Walk in Leiden

Continuing a series of irregular posts about wildlife-spotting (see also Learning to See and If There is No Home for Nature), today I went for a walk with my dad through the polder behind his house in Leiden, which means binoculars are in order.

Sheep grazing next to the lake

As always in Holland, water is never far away – there is a golf course where most of the holes are sandwiched between dykes and open water (which probably makes completing the course fairly challenging unless you have several spare balls handy!) and a nature reserve with lakes and spits of land giving lots of opportunities to spot birdlife. 

Wildlife on Holiday - Los Angeles

To what extent do geology, wildlife and climate help create culture and a sense of place? Over the last few weeks I've had the chance to explore this question in four cities with very different climates: Los Angeles, San Francisco, Seattle and Vancouver.
In LA, the climate is hot and dry, with the city built within a bowl of mountains between the ocean on one side and desert on the other. Some places like Arizona and Texas embrace the desert as part of who they are, creating gardens of succulents like the Tequila cactus (which I'm told produces a sweet drinkable sap) and hardy arbuto trees with amazing bark which eventually strips off entirely and locust trees. These plants are in evidence on the hillsides next to the freeways, but hardly visible in the city at all. Instead, Los Angeles seems to be a city of dreams: green grass, palm trees and eucalyptus sustained only by sprinkler systems.

Wildlife (and weeds) on track - October

My first site visit of October took me to a rural stretch of railway near Corby which included a stunning brick viaduct across a wide valley – the bridge has been repaired so often with so many different colours of brick that it’s hard to tell which are the original bricks!
On the wildlife front, we saw a stoat running along near the track, a hedgehog, a pheasant and several different butterflies.

Wildlife on Track - September

I have blogged previously about my efforts to spot wildlife and "get my eye in" so I thought a good challenge would be to record what I've seen on my various site visits this month, mostly to railways. I wonder what I'll see next month?