Glossary of Terms

Abutment
Supporting ends for a bridge deck; built as revetment walls either side of the watercourse.
Aggregate
Graded stone used to form the sub-base, base and surface of a path. Imported material available in a variety of grades.
Anchor bar
Stone structure built across the path to stabilise aggregate surfaces on slopes; deters down-hill slippage.
Back-fill
Mixed spoil - stone, minerals and soil, used to infill gap or space behind, or between stone work after pinning; also use to infill a borrow pit prior to turfing over.
Bare width
Survey term to describe the width of path that has no vegetation cover; where trampled or eroded away.
Batter
The backward leaning slope on the face of a retaining wall, or sides of a ditch; prevents wall from falling forward, ditch edges from collapsing.
Benching (in)
Excavation to build a path traversing a steep slope; maintains a flat surface (bench) by digging into the slope or building up lower edge.
Blockers
Boulder, turf or mounds positioned around the path to discourage walkers from taking short-cuts or leaving the path.
Block stone
Large stone used to construct drainage features, anchor bars etc.
Borrow pit
Small scale excavation, mini quarry, for winning materials (aggregate and surfacing), for path construction.
Braiding
Narrow path lines worn parallel to main path; caused by walkers deviating from an eroded, or damaged surface; can be numerous depending on severity of erosion, vegetation type etc.; join up to form wide erosion scars.
Bunds
Landscaped embankments at path edge, made of spoil and turf; used to channel walkers onto the restored path line.
Camber
Path surfaced with middle slightly higher than the sides; allows surface water to flow off to both sides.
Catchment
Area of ground around path where water collects in the form of bogs, surface water, springs, streams; affects path drainage.
Catch pit/Soakaway
Excavated to collect path drainage water where there is no natural outflow; also slows down water flow and collects debris.
CDM
Construction (Design and Management) Regulations, 1994; safety management from design stage to construction completion; relates to work lasting more than thirty days, or with more than five staff on site.
Chamfer
Cut back or bevel the sides of ditching and embankments, to give sloping surface (batter) and avoid unstable vertical sides.
Clinometer
Small instrument for measuring gradients (calibrated spirit level).
Course, of stone
Single row or line of construction stones on a revetment wall, pitched path etc..
Cross-drain
Open top drainage channel, typically lined with stone; used to direct water from one side of the path to the other
Cross-fall
Path surfaced with one edge higher than the other; allows surface water to flow off to the naturally draining slope or ditch.
Cross-slope
Slope across which the path traverses; land slopes up on one side of the path, and down on the other side.
Culvert
Generic term for drainage channel taking water from one side of the path to the other; closed stone box and piped culverts most common types used in pathwork.
Desire line
Preferred, or easiest line taken by walkers, often to landscape feature; not necessarily following the main path line.
Ditch/drain
Open channel used to catch, direct and disperse water flow.
Dynamism
Rate of change in path condition; depends on motive force of gradient, user numbers, water flow etc.. A highly dynamic path will erode quickly; a path with low dynamism will be relatively stable.
Face stone
Upstand or side stone of drain channel: waterbar, cross-drain or box culvert; the face is the side of the stone which channels the water flow.
Fall-line
Most direct line from the top of a slope downwards.
Fines
Smallest size of stone in graded aggregate; helps in compaction and used alone for binding the top surface of path.
Flag stone
Large slabs of stone, normally sandstone; used for top of boxed culverts.
Ford
Raised bed of watercourse taking path line through; often pitched to provide a good walking surface and to dissipate power of water flow.
Friable
Refers to stone that breaks up easily; often exposed and weathered stone with visible fractures.
Frost heave
Freeze thaw effect of water under and through the path surface; lifts and breaks up the surface or drainage features.
Geotextiles
Synthetic, or man-made materials used in road construction and landscaping; meshes and matting adapted to float paths over areas of deep peat; biodegradable meshes used in site restoration.
Gradient
Angle or slope of the ground or path; long gradient refers to the slope along the path line.
Gullying
Eroded channels formed on or alongside the path; loss of vegetation and soil by force of feet and water.
Hags
Small islands or banks of peat; formed by the surrounding ground eroding away by water, feet or grazing.
Humps and hollows
Landscaping technique to keep walkers on restored path line; banks and dips created from spoil and turf; tested on Ben Lomond.
In-fill
See back-fill.
In-flow/out-flow
Water channelled into and out of a path drainage feature by ditching.
Keystone
Final, or first stone, that is used to lock together a section of stonework, or provide a firm base stone e.g. in pitching or revetments.
Lett
Small open channel at path edge; dug, or stone constructed, to allow small amounts of surface water or puddles to drain from the path surface.
Liner
Base stones of drain feature providing the water channel; stops the front or base of the drain eroding away and sheds water and debris away.
Maintenance
Routine inspection and minor repair of paths on a regular basis; includes clearing out drains, surface repair, site restoration.
Mineral
Material (aggregate) composed of small stone particles exposed once peat or soils have been eroded, or excavated; used for path surfacing, or infilling gaps in stone work.
Peat hag
see hag
People counters
Electronic instruments installed to count path users; various types available - pressure mechanisms used under path surface; sensory mechanisms at path sides; counts carried out manually using recording sheets.
Pigeon-holing
Early sign of sheet erosion and gullying on steep slopes; walkers use same foot placements, causing concentrated vegetation and soil loss, appearing as series of “pigeon-holes” down the slope.
Pitching
Random sized and placed stone forming a hard wearing, rough cobbled, mini step like surface; predominantly used on steep gradients where erosion is severe.
Pinning
Small stone wedges used to prevent movement of structural stone used in pitching, drains, revetments etc..
Piped culvert
Drain channelling water across and under the path by means of a pipe; comes in a variety of materials, plastic most commonly used.
Remedial works
Repair work carried out under the contract; normally 9 to 12 months after completion of initial pathwork.
Revetment/ retaining wall
Formal or informal wall built to hold up unstable banks and steeply sloping ground; may be single or multiple course and above or below the path edge.
Re-vegetation
Restoring vegetation to eroded areas of ground; predominantly by turfing over erosion scars or by seeding and fertilising.
Scour
Water erosion of the path surface; forms small channels which may lead to severe gullying.
Splash plate
Stone placed at the outflow end of a culvert, waterbar or cross-drain; prevents water eroding the path edge at the end of the drain.
Tensar
Proprietary product - plastic mesh or grid; used to strengthen, stabilise and prevent lateral movement of aggregate path.
Terram
Proprietary product - woven matting used to “float” aggregate paths over peat or soft clay; strengthens construction and separates aggregate from underlying soil.
Trample width
Survey term to describe the width of ground, including the main path line, that shows signs of having been walked on.
Traverse
Path alignment which crosses a side slope, avoiding the straight down route of the fall-line.
Tray
Excavation for the new path surface along its length and width, prior to filling with aggregate or pitching.
Tread
Top surface of a pitched path or drain stone, which is used by walkers as a foothold to “tread” on.
Upstand
Height of a drain face stone above the liner, or the pitched path stone above the lower stone tread; forms the “depth” of the drain and deflects the water, or forms the height of the pitched “step”.
Variation
Used on a path contract to vary the specification or bill of order quantities; agreed in advance of the work being undertaken.
Waterbar
Drainage feature, usually stone, built across the path; diverts path surface water to the lower side slope.
Water-table
Natural water level of saturated ground; often underground.
Weathered/ lichened stone
Stone with a natural appearance caused by exposure to the elements for many years; may have lichens growing on its surface.
Zigzag
Path line descending a steep slope by using a snaking line of alternate angled traverses, rather than straight down the fall-line.