The Management of Bridges and other Highway Structures in West Berkshire.
This outlines West Berkshire Council’s procedures to ensure highway structures within
the district are safely and cost effectively maintained.
Contents:
1. Introduction
2. Inspections
3. Data Storage and the Bridge Management System (BMS)
4. Maintenance
1. Programming Maintenance Works
2. Minor Maintenance
3. Reactive and Emergency Works
4. Major Maintenance, Strengthening and Replacement
5. Highway Structures Owned and Maintained by Third Parties
1. The Load Bearing Obligations of Network Rail and British Waterways
6. Managing Structures that Cause Restrictions on the Highway
1. Weight Restrictions
2. Height Restrictions
3. Width Restrictions
7. Technical Approval and Commuted Sums
1. Technical Approval
2. Commuted Sums
8. Abnormal Load Movements and the Assessment of Structures.
1. Abnormal Load Movements
2. ESDAL
3. The Assessment of Structures
9. The Management of Bridges On and Near the District Boundaries
10. Future Bridge Management Requirements
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1. Introduction.
There are in excess of one thousand highway structures in West Berkshire District. These
include bridges, retaining walls, culverts, sign ganrtries and pedestrian subways.
Not all of these structures are owned by the Council, some are owned by other
organisations such as Network Rail and British Waterways however as the Highway
Authority the Council has a duty to ensure they are all maintained in a safe and functional
condition.
This the Council achieves by employing the following procedures.
 Undertaking routine inspections to ensure public safety and identify maintenance
needs.
 Undertaking minor maintenance works identified by routine inspections.
 Programming and executing maintenance work to minimise inconvenience to the
travelling public.
 Undertaking reactive and emergency repairs resulting from traffic accidents and
vehicle damage.
 Undertaking major maintenance and replacement works where structures have
reached the end of their service life.
 Imposing protection measures such as weight restrictions and traffic signals on
weak or impaired bridges.
 Retaining structures data and information on a comprehensive computerised
database.
 Checking the suitability and construction of all new highway structures through
the Technical Approvals process.
 Ensuring bridges owned by other organisations are maintained in a safe condition.
 Managing the safe movement of oversized or overweight vehicles known as
‘abnormal loads’ through the district.
 Predicting future aspirations for highway structures through consultation and
feasibility studies.
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2. Inspections
Highway Structures are routinely inspected to ensure they remain safe for public use. The
inspections also provide the data required to support good management practice in
accordance with the Road Liaison Group’s document: Management of Highway
Structures, A Code of Practice.
Maintenance work to Council owned structures is identified by inspection and placed in
the works program according to priority.
Structures owned and maintained by other organisations such as Network Rail, and
British Waterways are also inspected and any outstanding maintenance works notified to
the organisation concerned.
All highway structures are routinely inspected in the following cycle:
Principle Inspection
carried out not at intervals not greater than six years.
A close examination within touching distance of all
accessible parts of the structure. Specialised access
equipment may be required.
General Inspection
carried out not more than 2 years following the previous
General or Principal Inspection.
A visual examination of all parts of the structure where
special access equipment is not required.
Superficial Inspection
carried out not more than 2 years following the previous
Superficial on all private structures.
A visual examination of all parts of private structures
where special access equipment is not required.
Routine Surveillance
general surveillance by Highways Inspectors as part of
regular Highway Safety Inspections.
A visual examination identifying obvious defects requiring
urgent attention e.g. damage to parapets, superstructure,
joints.
The following inspections are carried out after one of the above inspections have
identified certain defects:
Safety Inspections
carried out after routine surveillance or after information is
received that indicates the structure is damaged.
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Inspections for Assessment
carried out after a particular defect is identified in a
previous inspection that may affect the structures load
carrying capacity.
Special Inspection
carried out after a particular defect is identified in a
previous inspection or event e.g. flooding, scour, vehicle
impact damage.
Acceptance Inspections
carried out due to a transfer of responsibility.
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3.
Data Storage and the Bridge Management System
The Council maintains a computerised database called ASTRA. It has been developed inhouse from a system known as COSMOS which was inherited from the former Berkshire
County Council. ASTRA holds important data about every highway structure in West
Berkshire including information about its condition at the time of its last inspection.
ASTRA will also compare the condition of any one structure to the condition of the other
structures held on the database thereby enabling maintenance works to be prioritised for
the structures in the poorest condition.
The Council is striving to achieve the standards of Asset Management and Performance
Measurement of Highway Structures recommended in the recently published Code of
Practice and referred to in the Council’s LTP2 document. To this end the Council is in
the process of procuring a new and more sophisticated electronic Bridge Management
System that will allow more detailed analysis of the maintenance requirements of
highway structures across the District.
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4. Maintenance
4.1. Programming Maintenance Works.
When programming maintenance work care is taken to minimise inconvenience to the
travelling public by:
 Selecting a repair method or technique that will cause minimal obstruction of the
highway.
 Providing traffic management appropriate to the type of road and expected traffic
flows.
 Programming works with regard to other road works in the area and the
availability of diversion routes.
4.2. Minor Maintenance
The bridge inspection regime is the main source of information identifying the routine
maintenance requirements of the structures stock.
There are complex formulae within the Bridge Management System that prioritise the
maintenance works identified by the routine inspections and from this an annual
programme of maintenance work is drawn up. Typical minor works are repointing and
brickwork repairs, the repair and replacement of handrails and parapets, repairs to
protective coatings and the repair or replacement of expansion joints.
Graffiti is removed from structures if it is considered to be offensive or unsightly.
Subways most commonly fall victim to graffiti and to counter this most of them have
been painted with anti-graffiti paint and are inspected and cleaned on a monthly basis.
4.3. Reactive and Emergency Repairs.
Vehicle collisions can severely damage highway structures and leave them in an unsafe
condition. In the worst cases this results in temporary road closures and diversions until
the necessary repairs can be made.
4.4. Major maintenance, Strengthening and Replacement.
As a structure approaches the end of its design life or service life it will usually become
uneconomical to repair and will require replacement. A structure may also become due
for replacement if it represents a restriction to the highway through being, for example,
too narrow, under strength or unsuitable for disabled use.
Recently Completed Bridge Replacement and Strengthening Schemes:
Blackboys Bridge, Newbury
Parkway Bridge, Newbury
Kennet and Avon Canal Bridge, Hungerford High Street
Basildon Skew Bridge, Basildon
Alfrey’s Rail Bridge, Beech Hill
Swan Footbridge, Great Shefford
Programmed Bridge Replacement and Strengthening Schemes:
Northcroft Canal Footbridge (Monkey Bridge), Newbury
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5. Highway Structures Owned and Maintained by Third Parties.
Approximately one third of structures on West Berkshire’s highways are owned and
maintained by third parties. Network Rail, the Highways Agency, the Environment
Agency, British Waterways, local land owners and businesses all own bridges and
structures that affect the highway in some way.
The Council undertakes routine ‘Superficial’ inspections of these structures to ensure
they are maintained in a condition that will not endanger the travelling public. The
Council will notify the bridge owner if a bridge is found to be in a dangerous condition
and take enforcement action if the owner fails to take remedial action.
5.1. The load bearing obligations of Network Rail and British Waterways.
Most of the bridges in West Berkshire that have weight restrictions are owned by either
Network Rail or British Waterways. Due to an anomaly in highway legislation these
organisations have a legal obligation to maintain their bridges to 24 tonnes to an old
assessment standard known as BE4. However the permissible maximum weight of
vehicles using the highway is currently 40 tonnes. The Council as the Highway Authority
is required to assess the strength of bridges to a more modern standard than BE4 known
as BD21/01. This is more onerous than BE4 hence some Network Rail and British
Waterways bridges have weight restrictions on them less than 24 tonnes.
Network Rail’s bridges in West Berkshire were recently assessed jointly by Network Rail
and West Berkshire Council in accordance with the Bridgeguard Three Agreement.
Bridgeguard Three is a protocol agreed nationally between The County Surveyor's
Society and Network Rail for the protection of Network Rail’s bridges.
Since its creation in 1998 West Berkshire Council has taken ownership of and
strengthened or replaced three strategically important bridges, Blackboy’s Bridge
(completed Dec 1999), Basildon Skew Bridge (both bridges were previously owned by
Network Rail) and Hungerford Canal Bridge (previously owned by British Waterways).
The Council also financed the strengthening of Alfrey’s Rail Bridge in Grazeley, in 2006,
another Network Rail owned bridge.
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6. Managing Structures that cause Restrictions to the Highway
There are three ways in which bridges can restrict or impair highway usage,
weight restrictions, height restrictions, and width restrictions.
6.1. Weight Restrictions
There are two types or weight restriction, environmental and structural. Environmental
restrictions are applied to lengths of road that are unsuitable to carry heavy vehicles and
are not related to bridges. Structural weight restrictions are applied specifically to protect
weak bridges.
Table 1. Structural Weight Restrictions on Bridges in West Berkshire.
Bridge Name
Parish
Bridge Owner
Restriction
Network Rail
Type of
Restriction
Temporary
Pingewood
North
Boundary Road
Aldermaston
Station.
Ufton Swing
Bridge
Tyle Mill
Swing Bridge
Theale Swing
Bridge
Tyle Mill River
Whitchurch
Toll Bridge
Burghfield
Newbury
Padworth
Network Rail
Network Rail
Permanent
Temporary
3 tonnes
3 tonnes
Ufton Nervet
British
Waterways
British
Waterways
British
Waterways
WBDC
Private
ownership
Permanent
5 tonnes
Permanent
5 tonnes
Permanent
3 tonnes
Permanent
Permanent
7.5 tonnes
7.5 tonnes
Sulhamstead
Theale
Sulhamstead
Oxfordshire
boundary
3 tonnes
From the above table it can be seen that most of bridges with weight restrictions in West
Berkshire are owned by Network Rail and British Waterways. This is for the reasons
explained in paragraph 5.1. The load bearing obligations of Network Rail and British
Waterways. These bridges are all on minor roads and the weight restrictions have no
significant affect on vehicle movements across the District. Tyle Mill River Bridge,
owned by West Berkshire Council, adjoins Tyle Mill Swing Bridge and would be of no
benefit to strengthen due to the restriction on the swing bridge.
6.2. Height (or Headroom) Restrictions
The standard minimum clearance over every part of the carriageway of a public highway
is 16 feet six inches (5.03 metres). Height restrictions in West Berkshire are managed by
the provision of advance warning signs on routes leading to the bridge and statutory signs
at the bridge. There are more technically advanced warning methods available for bridges
that are repeatedly struck by high vehicles. These are usually installed at the behest of
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Network Rail, however they can be problematic and there are currently no bridges in
West Berkshire that warrant their use.
Table 2. Height Restrictions in West Berkshire.
Bridge Name
Marsh Lane
Parish/Town
Hungerford
Bridge Owner
Network Rail
Parsonage Lane
Hungerford
Network Rail
Croft Road
Hungerford
Network Rail
Hungerford High
Street
Inglewood Gate
Arch
Marlston Road
Bridge (disused)
Eling Road
(disused)
Compton Bridge
(disused)
Pangbourne Station
Arch
Whitchurch Railway
Arch
Pound Green Bridge
Hungerford
Network Rail
Kinterbury
Private
Hermitage
Pangbourne
West Berkshire
Council
West Berkshire
Council
West Berkshire
Council
Network Rail
Pangbourne
Network Rail
Wokefield
Network Rail
Hampstead Norreys
Compton
Height Restriction
12 feet 6 inches
(3.81 metres)
11 feet 3 inches
(3.42 metres)
13 feet 3 inches
(4.03 metres)
15 feet 6 inches
(4.70 metres)
15 feet
(4.57 metres)
13 feet
(3.96 metres)
12 feet 9 inches
(3.88 metres)
13 feet 6 inches
(4.1 metres)
13 feet 3 inches
(4.03 metres)
11 feet
(3.35 metres)
12 feet 9 inches
(3.88 metres)
Generally the cost inhibits raising the headroom under any of the Network Rail owned
structures. There has, in the past, been requests for the demolition of both Compton and
Marston Road disused bridges however public and Parish Council opinion is currently
opposed to this as the bridges are now perceived to be performing important traffic
management functions.
6.3. Width Restrictions
There are various ways of managing width restrictions to the highway caused by narrow
bridges. The most suitable method will depend on various site conditions such as the
severity of the restriction, traffic flows and sight lines. Narrow bridges may restrict either
the carriageway width (Aldermaston Wharf Lifting Bridge) or footway widths
(Hungerford Canal Bridge). If traffic flows and sight lines allow priority traffic signs are
usually the preferred option. On busier roads or where safety is a concern traffic signals
are used (Basildon Skew Bridge, Smallmead Bridge).
Two of the most problematic width restrictions caused by bridges are at Hungerford
Canal Bridge-footways and Aldermaston Wharf Lifting Bridge-carriageway. A feasibility
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study has been undertaken to investigate possible improvements at Aldermaston Wharf
Lifting Bridge and one is currently underway for the provision of a new footbridge
alongside Hungerford Canal Bridge.
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7.
Technical Approval and Commuted Sums
7.1 Technical Approval
West Berkshire Council as the Highway Authority ensures that all structures which are
constructed over, under or next to the public highway are constructed to an acceptable
standard by requiring them to achieve ‘Technical Approval’. Some highway structures
may remain in private ownership but in most cases the Council will ‘adopt’ or take
ownership of the new structures. In either instance Technical Approval is required.
In normal circumstances only structures that are a necessary part of the highway and
constructed on highway land will be considered for adoption. These may include road
bridges, public footbridges, culverts, retaining walls that support the highway and sign
gantries. When the Council is agrees to adopt a structure an additional adoption
Agreement will be drawn up by the Council.
Structures that remain in private ownership require Technical Approval only. These may
include private road bridges and footbridges over the highway, retaining walls more than
1.5 metres high above ground level that support property or land adjacent to the highway,
support structures for pipes and conveyers which cross the highway, basements which
support the highway, parts of buildings which cross or overhang the highway, temporary
structures intended for public use etc. Private structures which cross the highway also
require a licence which will be drawn up by the Council.
7.2 Commuted Sums
When the Council is required to adopt a new structure from a private enterprise or
developer it will usually require them to pay a ‘Commuted Sum’ to the Council. The
commuted sum is equal to the costs the Council may expect to incur for maintenance,
inspection and renewal of the structure and is usually calculated over a period of one
hundred and twenty years.
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8.
Abnormal Load Movements
8.1 Abnormal Load Movements
An abnormal load is a vehicle that is outside the classification of normal permitted traffic
by virtue of its gross weight, length, width or axle configuration according to current road
vehicle regulations. In accordance with The Road Vehicles (Authorisation of Special
Types) General Order 2003 the movement of abnormal or STGO loads should be notified
to the relevant Highway Authority or Authorities.
Jacobs Babtie currently act as West Berkshire Council's appointed agent to receive
notifications for the movement of abnormal loads and STGO vehicles on non-trunk roads
in West Berkshire. Jacobs Babtie are also appointed agents for Reading, Bracknell Forest,
Windsor and Maidenhead and Slough Councils and Rail Property. Notifications should
be faxed directly to their Reading office (Fax No. 0118 9881 656).
The movement of abnormal loads needs to be carefully managed so that large and heavy
vehicles only use those parts of the road network that can safely accommodate them.
Hauliers of abnormal loads are required to notify the appointed Abnormal Loads Officer
at Jacobs Babtie. The bridges on the notified route are then assessed in accordance with
the current requirements of the Design Manual for Roads and Bridges (BD 86/01) and the
code of Practice for the Management of Highway Structures. If any of the bridges on the
route are considered too weak to bear the abnormal load it will be re-routed. If no suitable
alternative route is available special measures to increase the load bearing capacity of the
bridge may be considered.
8.2 ESDAL
ESDAL stands for "Electronic Service Delivery for Abnormal Loads Project". Once fully
implemented ESDAL will be a national one-stop web-based portal to assist route
planning and automated notification of abnormal load movements.
At present, before moving an abnormal load, hauliers must notify a number of authorities,
including the Highways Agency, Agents, Local Authorities, private bridge owners and
the Police. This is a lengthy process and is entirely manual, based on the use of faxes to
exchange and agree information.
The ESDAL project will simplify this process, significantly reducing the amount of time
it takes for everyone involved in the process to plan, notify and approve the movement of
an abnormal load.
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8.3 The Assessment of Structures
Highway structures are assessed to establish their ability to carry the loads which are
imposed upon them. The assessment provides valuable information for managing the
safety and serviceability of highway structures.
The road bridges in West Berkshire were last assessed under a national programme of
assessment undertaken in the mid 1980s.
In accordance with the recommendations of the new Code of Practice West Berkshire
Council is currently undergoing a Structural Review. This involves revisiting the existing
assessment information and from this developing a prioritised reassessment programme.
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9.
The Management of Bridges On or Near the District Boundaries.
West Berkshire District has five neighbouring Authorities: Wiltshire, Hampshire,
Oxfordshire, Reading and Wokingham. To avoid any confusion bridges near to or on the
boundaries are subject to Maintenance Agreements whereby the maintenance of the
bridge is delegated to one or other of the Authorities. Agreements are in place with
Hampshire and Oxfordshire for bridges over the Rivers Enborne and Thames
respectively. The Council remains in close consultation with all neighbouring Authorities
regarding bridge restrictions and maintenance works that may affect the highway network
beyond West Berkshire’s boundaries.
Whitchurch Toll Bridge, which crosses the River Thames at Pangbourne, is currently
managed by Oxfordshire County Council on behalf of the bridge owners, "The Company
of Proprietors of Whitchurch Bridge". The bridge currently has a 7.5 tonne weight
restriction. Major reconstruction is planned for 2013 which will require the bridge to be
closed for approximately three months.
.
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10. Future Bridge Management Requirements.
In September 2005 The Roads Liaison Group launched a Code of Practice for the
Management of Highway Structures. Prior to the publication of the Code of Practice there
was no overarching document available to guide bridge owners on good maintenance
practice and this has led to differing practices across the country. The purpose of the code
is to standardise practice thereby providing better information regarding the condition of
bridges across the county and so determine future funding requirements.
West Berkshire Council’s current practice generally aligns very well with the basic
recommendations made in the new code of practice. It is the Council’s intention to
become fully compliant with the code within the recommended time frame of 5 years by
the development of asset management principles set out in the new code.
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