GB2449481A

GB2449481A - Electrically insulating rail joints

Info

Publication number: GB2449481A
Application number: GB0709972A
Authority: GB
Inventors: Alan Lawson; Alan Hanbury
Original assignee: Henkel Loctite Adhesives Ltd
Current assignee: Henkel Loctite Adhesives Ltd
Priority date: 2007-05-24
Filing date: 2007-05-24
Publication date: 2008-11-26
Also published as: GB0709972D0

Abstract

A process for electrically insulating joints between two adjacent metal rail sections comprises the application of a curable insulating material 24, e.g. adhesive resin or polyurethane based, into a gap between adjacent rail sections at the joint. Initially, the joint may be bridged by deformed rail end material and/or debris. An angle grinder is used to remove the rail material and ensure a minimum gap extent. A compressed source is provided to supply air or cleaning fluid to remove any debris. The curable material 24 is applied by a dispensing gun 25 and excess material subsequently smoothed off or a mould fitting across and around the gap is used.

Description

Title 2449481 Insulated Rail Joints

Background to the Invention

The present invention relates to insulating rail joints. While the present invention is contemplated for use with in particular in-situ insulation of rail joints already laid down, it may be employed with fresh track to be laid or old track being re-laid.

Most modern railway systems can detect the presence of rolling stock on sections of the track. The presence of a train provides an electrical short circuit between the two (opposing) rails, which is used to indicate the track is occupied. Each block of track is monitored to provide signalling and blocks of track are isolated from adjacent sections by insulated gaps to form an insulated rail joint.

Failure at insulated rail joints cause incorrect signalling. Failure of insulated rail joints can result from "upping", a process caused by rail flow due to the passage of trains.

Lipping can cause the two adjacent rail sections or blocks to touch causing track circuit failure. Lipping will provide an electrical connection between adjacent blocks as the weight of the rolling stock gradually extends the ductile metal across the gap. Once an electrical connection is provided a train present in either one of the adjacent blocks will cause the monitoring system to incorrectly signal that both blocks are occupied. The train will be forced to stop and confirm that the railway is clear and the occupied signal * *..

is an incorrect signal before proceeding. *S*.

:.: : Where a short circuit has occurred and the rail monitoring system incorrectly indicates * that the section of the rail is occupied, an approaching train may be faced with an * * ** automatic stop signal at the section of the rail in question. In current rail systems every precaution needs to be taken to ensure the safety of passengers, therefore even if the * S * * * train driver can clearly perceive that the section of the rail is not occupied it will still be necessary to stop the train. Train drivers are then required to contact the control center and confirm that that they can see no obstruction ahead before the control center will lift the restriction manually. This can cause significant and unnecessary delays in train journeys thereby adversely affecting the efficiency of the rail service.

Existing repair processes are expensive and time consuming. Repair of such failures presently involve a new, factory fitted insulated rail joint to be spliced into the track.

This process involves cutting out a section of track including the joint and installing a new section. This operation requires significant engineering work that results in a significant disruption to rail services. There is a need in the art for a quick and inexpensive process for the repair of failed insulating joints. There is also a need in the art for insulating rail joints that are robust.

In many cases an electrical contact between adjacent rail blocks will be caused due to debris such as rubbish, dirt or crud filling the insulating gap between adjacent rail blocks. There is a need in the art for insulated rail joints that cannot be shorted by the presence of dirt and rubbish in the insulating gap.

There is clearly a need for a more efficient process of repair.

Summary of the Invention

The present invention relates to a process for electrically insulating rail joints between two adjacent metal rail sections, the process comprising the step of, applying a curable :. insulating material into a gap between adjacent rail sections at the joint. * * * *S*.

An electrical contact existing between two adjacent track blocks will result in an : : electrical short circuit at the insulating rail joint and ultimately will result in incorrect signalling in the rail system. An electrical contact between the two adjacent tracks may be formed by at least one of upping, dirt, curd, rubbish or any other electrically ***.

conductive material. Lipping occurs when metal from one or more rails bridges the gap * S S S * between adjacent rail sections thus creating an electrical contact between the adjacent rail sections which are otherwise electrically isolated. Where a train position monitoring circuit is employed this results in track circuit failure. Lipping usually occurs as a result of rail flow.

The present process of the invention thus repairs shorted insulated rail joints. The inventive process may involve the step of first removing any electrical contact between the adjacent metal rail sections, before, applying, in-situ, a curable insulating material into a gap between adjacent rail sections at the joint. The in-situ process allows the track joint to be repaired without the removal of whole track sections which occurs at present.

In-situ repair makes the overall repair process less time consuming and less expensive then existing repair methods.

The step of removing any electrical contact between the adjacent rail sections comprises the step of removing any conductive material bridging the gap between rail sections.

Sufficient amounts of rail material should be removed so that any bridging is removed and a gap is formed suitable for being filled with a curable insulating material.

Since an electrical connection may also be formed by debris bridging the gap between rail sections, the repair process may involve the alternative or additional step of removing any debris that exists in the gap between rail sections. Sufficient amounts of debris should be removed so that there is no longer debris bridging between rail sections.

If the electrical contact between the adjacent rail sections is provided by both, metal from one or more rails bridging the gap between rail sections and debris bridging the :. gap between rail sections, the repair process will involve the step of removing sufficient amounts of rail material and removing sufficient amounts of the debris lodged in the gap **I.

between rail sections, to ensure no electrical contact is formed between the rail sections. * ** * S S S.. *

The gap formed for receiving the curable material will usually be cut into any pre-existing insulation material that exists between the rail sections. More often then not the S * *S..

removal of the pre-existing insulation material or the electrical contact, for example lipping, is done utilising a cutting tool such as an angle grinder. However any suitable cutting tool may be used. The gap cut between the rail sections using the cutting tool will usually be between 3 to 10 mm wide for example 3 to 8 mm wide and I to 10 cm deep for example 3 to 8 cm deep. Most preferably the gap cut is about 4mm wide and about 5cm in depth. The dimensions of the gap should be sufficient to allow sufficient fill of the insulating filler and the dimensions mentioned herein allow sufficient fill.

Where the electrical contact is formed by debris, the contact may be removed using a blast of a fluid such as air.

It is important to remove any contaminants that may exist on the surfaces of the gap to be filled and which may interfere with curing of the curable material. In light of this the process may involve the step of removing any contaminants that may exist on the surfaces of the gap to be filled. This may be done using an air gun or any other suitable apparatus. Once the gap surfaces have been cleaned the proceeding step will involve applying at least a sufficient amount of curable material to fill the gap. The absence of insulating "gaps" make the new rail joints robust against shorting for example the adjacent rail blocks cannot be shorted by the presence of dirt and rubbish in the insulating gap. Overall the insulating joint is less vulnerable to track circuit failure.

Many materials may be used to fill the gap between the rail sections for example adhesive materials including polyurethane-based material. Preferably the curing material is an adhesive material such as an adhesive resin and includes materials such as, MS polymer based materials; two-part polyurethanes; two-part epoxies; two-part silicones; two-part acrylics; UV or visible light curing acrylics; UV or visible light curing epoxies.

:. A suitable two-part polyurethane may include as a first part a curable resin component for example MID! (Methylene diphenyl diisocyanate) and a second (separate) part ***.

comprising a curative component for example a polyol. The composition may comprise : additional components. For example the curable resin part of the composition may include one or more of a filler, for example calcium carbonate, a desiccant, a flexibiliser for example alkylsulphonic phenyl ester, DINP (diisononyl phthalate). The curative :::: part of the composition may include a catalyst such as an organic amine, a filler such as calcium carbonate, a desiccant, a flexibiliser for example alkylsuiphonic phenyl ester, DINP.

One example of a commercially available two-part polyurethane composition suitable for use with the present invention is Teromix such as Teromix 6700 which is available from Henkel KGaA in Dusseldorf, Germany.

MS polymer is a reactive polymer available from Kaneka Belgium, NV which is a silyl-terminated polyether. In particular it contains polypropyleneoxide as the main chain and dimethoxysilyl groups as terminal groups. It is curable by moisture and by a hardening catalyst.

io A suitable formulation includes a curable component which is a polypropylene glycol (molecular weight 8000-14,000) endcapped with alkoxysilane and a curative for example a catalyst such as a salt of tin. The curable component may be present in the range of 25-45 % w/w. The catalyst may be present in amounts from 0.1 to 0.6 % w/w.

A reinforcing filler such as calcium carbonate may be employed for example in the range from 3 5-50 % w/w. Additionally an adhesion promoting agent such as an aminosilane, for example in the range 0.1-2 % w/w and/or alkoxy silane, for example in the range 1-4 % w/w. may be employed. Further components such as plasticisers, for example alkylsuiphonic phenyl ester, DINP, may be employed in the range from 10- 30% w/w. A filler or pigment such as carbon black, optionally in the range 0.5-2 % w/w may be employed.

A suitable two-part epoxy may include (i) a curable epoxy resin component, for :. example Bis A DiGlycidyl ether; (ii) a (separated) curative component for example an amine. The epoxy may optionally include one or more of: a toughening agent such as rubber; a flexibiliser for example a polyol; filler for example quartz and/or talc. * ** * * S S.. *

** A suitable one-part epoxy may include (i) a curable epoxy resin component, for example Bis A DiGlycidyl ether; and (ii) a curative component for example an photoinitiator. The epoxy may optionally include one or more of: a toughening agent such as a core shell polymer a flexibiliser for example a polyol; filler for example quartz and/or talc. Generally one-part epoxy compositions require a relatively high temperature cure so such systems are probably best suited to off-site repair and/or for new track.

A siloxy (often referred to as silicone) material may include: a curable siloxane such as a hydroxy polymethylsiloxane optionally endcapped with alkoxysilane and a curative for example a catalyst such as a salt of tin. The siloxane component may be present in the range of 40-60% w/w. The catalyst may be present in amounts from 0.1 to 0.3% w/w. A reinforcing filler such as calcium carbonate may be employed for example in the range from 3 5-45 % w/w. A further rheology modifier (particularly for viscosity parameters) such as fumed silica, optionally in the range from 2-7% w/w may be employed. Additionally an adhesion promoting agent such as an amino silane, for example in the range 0.1-1% w/w and/or alkoxysilane, for example in the range 1-4% w/w may be used. Further components such as plasticiser for example methyl terminated polydimethylsiloxane may be employed optionally in the range from 1-10% w/w. A filler or pigment such as carbon black: optionally in the range 0.5-2% w/w may be employed.

The adhesive material will bond within the gap to the rail sections. The filler will be selected by virtue of its properties. Some desirable properties include sufficient adhesion properties to withstand the movement of the joint caused by rail traffic. This includes sufficient adhesion strength to remain in place and not to disintegrate and fall out of the joint over time. It is desirable that the filler can adhere sufficiently to surfaces that may not be completely clean.

Furthermore the fillers selected should posses the required flexibility to withstand the tensile and compressive stresses that the track lines may exert on the fillers as a result of thermal expansion and contraction.

There exists many other options in relation to what material can be selected as a curable S.. * insulating material for applying into a gap between adjacent rail sections. The insulating material used in the present invention is desirably a quick curing material which lends *S..

itself to a fast repair process. Existing repair methods are slow and result in prolonged S. ** * S * . . . . . . disruptions to rail services. The method of this invention provides a quick and easy repair process that uses fast curing materials thereby minimising the disruptions to the rail service and increasing the overall efficiency of the rail service.

Optionally the curable material may be a two-part curable composition. In cases involving the repair of existing insulated rail joints (on already laid track), these curable materials are applied in-situ to a laid railway track to form an insulated rail joint.

However it is also possible that these materials can be used on pre-formed rail joints on track that is not yet laid. Once the curing material has been laid a rail track incorporating an insulated rail-joint will be formed.

The curable material used in the present invention has the desired insulating properties to insulate adjacent blocks of track. The curable material has desired adhesion properties to allow the material to bond to the rail and other elements of the insulated rail joint.

The adhesion is sufficient to resist vibration from trains as well as thermal extension and contraction that is exerted on the joint by the rails due to temperature variations including thermal shocks. Furthermore the curable material is resistant to flexing caused by passing trains. The viscosity of the curable material when heated to a high temperature may be such as to prevent the material flowing outside the joint during the repair process yet flowable enough to penetrate and fill the gap and form a contact with the entire bonding surface that is available. Since one of the objectives of the present invention is to provide a fast repair procedure the cure speed is an important criterion.

For example the curing material may have a curing speed of within one hour and desirably less, for example less than 30 minutes suitably less than 20 minutes. Variation in weather conditions also means that it is desirable that the curable material is capable of curing across a range of temperatures (for example -20 C to 40 C) and a wide range of weather conditions for example wet or dry. To ensure the quality of the insulated rail joint the curable material should be resistant to weathering and should be UV stable. For * * S...

a robust joint the curable material will also be chemical resistant, such that it is resistant .: to mild chemical attack for example oils and greases etc. Cross-linked materials may *. have desirable properties in this respect. *S..

The curable material may be applied into the gap using a dispenser such as a dispensing * 30 container or gun. The dispenser will allow the controlled application of the curable material to the gap. Optionally a mould may be positioned at the joint so as to shape the curable material to the profile of the rail sections. The mould will provide support walls at the edges of the insulating gap to prevent the curable material from flowing outside the edges of the insulating gap and it will also prevent excess curable material from being applied to the gap which would otherwise be disposed of as waste. Optionally thereafter the any excess material may be smoothed off so that the curable material is flush with at least the top surface of the rail sections. The mould being supplied is an applicator for fitting to the rails or for fitting to the dispenser.

Brief Description of the Drawin!s

Figure 1 shows a schematic of the basic principle of rail track circuits used to detect the presence of rolling stock on a section of track.

Figure 2 shows a side view of a failed insulated rail joint.

Figure 2A shows a side view of a rail joint wherein the ductile ends of the adjacent rail sections have been extended so as to bridge the insulating gap between the adjacent rails.

Figure 3 shows a perspective view of the first step in the repair process which involves cutting a gap in the rail section suitable for receiving curable material.

Figure 4 shows a perspective view of the second step in the repair process which involves the elimination of contaminants using an air gun. 0* * * *

Figure 5 shows a perspective view of the third step in the process which involves filling * the gap using curable material. * *a * * * *** .

*. Figure 6 shows a perspective view of the completed repaired insulated rail joint. *.i * *S*. *s *s * * *

* 30 Detailed Description of the Drawings

Figure 1 shows a schematic of the basic principle of rail track circuits used to detect the presence of rolling stock on a section of track. The railway track I consists of a left 2 and right 3 rail which run perpendicular to mounting sleepers 5 positioned at regular intervals. Figure 1 show a block "L" of the complete railway line 1. The rail way track I is subdivided by insulating gaps into blocks. The block "L" is defined by insulating gaps 6 and 7 which are located at either end of the block. Each block is connected to an energising battery 8. One of the rails 2 of the block section "L" is connected to the positive terminal of the energising battery 8 and the second rail 3 of the block section is connected to the negative terminal of the energising battery 8. The circuit can be completed by the presence of an electrically conductive rolling stock located in the block section "L", connecting both rails 2 and 3. Without the presence of a conductive rolling stock the circuit is incomplete.

Figure 1 shows block "L" further connected to an electromagnet 9. The electromagnet is used to control a switch 10. The electromagnet can position the switch 10 in and on or off position. The switch 10 will be moved into the on position when the electro magnet is activated and the switch 10 will be moved into the off position when the electro magnet is deactivated. The electro magnet is activated by providing an electrical connection between both rail 2 and 3 and thereby completing the circuit of the energising battery 8 and allowing current to flow to the electro magnet. When the circuit is complete the electromagnet is activated and this in turn activates switch 10.

The switch 10 controls a signal display apparatus 11. The display apparatus will have at least a "stop" 12 and "go" 13 signal. Once the switch is moved into the on position the signal display apparatus will display a "stop " signal. Each consecutive block in the rail system will have a similar construction to allow positional detection of a train along a S...

* * 25 line. S... * S. * * .

Figure 1 shows block "L" occupied by a rolling stock 4 comprising wheels and an axle. *

The rolling stock is electrically conductive and will thus provide an electrical * *.. connection between the left 2 and right 3 rails. The rolling stock 4 completes the *...

.: 30 detection circuit and this will allow current to flow through the windings 29 of the electro magnet. Once current flows through the windings the core of the electromagnet is magnetised and the electromagnet is fully activated. The activated electromagnet moves switch 10 into the "on" position and the display signal displays a "stop" signal 12. The presence of rolling stock has been detected and an appropriate stop signal has been activated to prevent other rolling stock entering the occupied section of track.

Over time the insulating gaps 6 and 7 that divide the railway line 1 into isolated sections may become bridged and this will result in failure at the insulating joints 30 and 31.

Failure of insulated rail joints 30,31 can result from "lipping", a process caused by rail flow due to the passage of trains. Lipping can cause two adjacent rail section sections or blocks to touch causing track circuit failure in the sense that isolated sections of track are no longer independently monitorable. Lipping will provide an electrical connection between adjacent blocks as the weight of the rolling stock 4 gradually extends the ductile metal across the gap. Once an electrical connection is provided a train present in either one of the adjacent blocks will cause the monitoring system to incorrectly signal that both blocks are occupied. This may cause a train to be detected in two or more sections even though it is not present in at least one of those. The train can thus generate a stop signal in a section of track it has not yet rolled onto. In the detection system above this will cause a stop signal to display as the forward rail section is detected as being occupied. The train thus generates a false stop signal for itself by virtue of being detected at a position forward of its actual position on the tracks. The train will be forced to stop and the operator will have to confirm that the railway is clear and the occupied signal is an incorrect (false) signal before proceeding.

Figure 2A shows a side view of an insulating joint 14 wherein the ductile ends of the adjacent blocks 15 and 16 have been extended so as to bridge the insulating gap 32. An electncal conductive contact is made at point 18 where hpping 20 occurs and the metal from one block touches the metal of the adjacent block causing a failed insulated rail : .. joint. S.. *

S

Figure 2 also shows a side view of the insulating joint 14 and adjacent blocks 15 and 16 * * and insulating gap 32 therebetween. Figure 2 further displays an electrical contact *. *.

: * * 30 between adjacent rail blocks, caused by debris such as rubbish/dirt 17 filling the gap 32 between adjacent rail blocks 15 and 16.

The present invention proposes to overcome the problem of failing insulated rail joints and further provides a repair process for failed insulated rail joints. The invention relates to a process for electrically insulating rail joints between two adjacent metal rail sections, the process comprises the step of applying a curable insulating material into a gap between adjacent rail sections at the joint.

Figure 3 shows step one in the repair process. The step involves removing any electrical contact between the adjacent metal rail sections, which includes the removal of any conductive material bridging the gap between rail sections (for example the bridging seen in Figure 2A). Figure 3 shows the insulating gap 14 (as shown in Figure 2) being worked on by a skilled person. The skilled technician uses a cutting tool such as an angle grinder 19 for the removal of the upping 20 which occurs at point 18. In addition the technician will remove a sufficient amount of any pre-existing insulation material 21 to provide a gap suitable for receiving the curable insulating material. The gap cut should be within the region of 3 to 10 mm wide and 1 to 10 cm deep between the rail sections. Desirably the gap cut is about 4mm wide and about 5cm in depth.

If debris has collected in the insulating gap 32 this must also be removed. Dirt, rubbish 17 and crud collecting in the insulating gap may also form and electrical connection between adjacent blocks of rail. Optionally a blast of fluid such as air from a compressed source such as an airgun or suitable apparatus may be used for the removal of such debris. It will be appreciated that a cleaning fluid, such as from a compressed source can also be employed. Cleaner surfaces of the rails will allow better bonding. * S * *S*

*::::* 25 Figure 4 shows the gap 22 cut in the pre-existing insulating material 21 using the cutting * tool 19. The gap cut should be large enough to receive the insulating filler and to allow sufficient surface area for the filler to adhere to inside of the gap. Figure 4 further *** shows the next step in the repair process. Figure 4 shows the technician removing contaminants that exist on the surfaces of the gap 22 to be filled. These contaminants S...

r* :* 30 would otherwise interfere with the curing of the curable material. If these contaminants are not removed they may also interfere with the bonding of the curable material to the rail sections 33,34. Figure 4 shows how a can of pressurised fluid 23 (for example an air brush) is used for the removal of the contaminants. The can 23 is directed to all the available surfaces inside the gap 22 so as to remove as much contamination as possible.

The process is not restricted to the use of a can of pressurised fluid and any suitable apparatus may be used.

Once the gap has been cleaned of any contaminants the gap may be filled using a suitable filler optionally by first priming the surfaces. Figure 5 shows the gap 22 being filled by a curable material 24, the curable material used in this example is an adhesive resin. The curable material 24 is applied in-situ to the laid railway track 1. The curable material 24 is applied into the gap 22 using a dispenser such as a dispensing gun 25.

Optionally a mould may be positioned at the joint so as to shape the curable material to the profile of the rail sections. This mould may be disposable. The mould will provide supporting walls that prevent the extrusion of the filler material from the gap sides.

Furthermore the mould will prevent excess material being added to the gap with would otherwise be disposed of as waste.

Optionally the curable material maybe a polyurethane-based material. It maybe a two-part curable composition. Further still the curable material may be at least one of Teromix 2 part, two-part MS polymer, two-part polyurethanes; two-part epoxies; two-part silicones; two-part Acrylics; UVfLight curing acrylics; U\'fLight curing epoxies.

Enough curable material 24 should be added to fill the gap 22 completely. The curable material 24 may be any suitable insulating filler material. Finally once the gap 22 has been filled with curable material 24 and before the material has cured, any excess material may be smoothed off (may not be necessary where a mould is used) so that the filler material is flush with at least the top surface 27 of the rail sections 26.

* ** Alternatively the insulating material may be smoothed off after curing using a suitable tool. Figure 6 shows the gap filled with insulating material with the excess curable material 24 has been smoothed off so that the filler is flush with the top 27 of the rail * S. sections 26. An insulated rail-joint 28 is formed by the process (when the material has **S.

:.. 30 cured). The rail track 26 incorporates the insulated rail-joint 28. * I

The skilled person will know to select suitable filler materials. Some of the properties required are discussed below.

The material should have sufficient adhesion to withstand the constant flow of rail traffic. Fillers that do no possess sufficient adhesion strength will not adhere well to the adjacent track lines and tend to rattle out of the joint over time. The adhesion of the filler should be sufficient so that it can adhere sufficiently to surfaces that may not be completely clean. The filler will also need to posses the required flexibility to withstand the tensile and compressive stresses that the track lines may exert on the fillers as a result of thermal expansion andcontraction. As will be appreciated, in warm weather the track lines will tend to heat up and this can result in thermal expansion of the track lines, thereby exerting a compressive stress on the insulated fillers, likewise in colder weather the track lines will contract exerting a tensile stress on the insulating filler.

There is therefore a need for a suitable insulating filler that has the required adhesion properties to withstand the passing of carriages, can adhere sufficiently to surfaces that are not completely clean, and has a suitable modulus of elasticity to withstand thermal contraction and expansion of the rail tracks.

While instant cure materials are not required, it is desirable that cure occurs over a suitably short period of time. Assuming that rail traffic may be prohibited until cure is complete slow curing materials may need to be avoided even if they otherwise fulfil the required properties. Slow curing fillers will slow down the repair process and result in longer disruptions to rail services. Generally a curing period of 2 hours or less may be useful for example 1 hour or less. * * * *S*

The words "comprises/comprising" and the words "having/including" when used herein * with reference to the present invention are used to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of *** one or more other features, integers, steps, components or groups thereof. *.S. * * S*.

* :* 30 It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. * * * **. *S*. * * **S. * ** * * S S.. *

S S.. * ** * S S... S. ** * * .

S

Claims

Claims 1. A process for electrically insulating rail joints between two

adjacent metal rail sections, the process comprising the step of: applying a curable insulating material into a gap between adjacent rail sections at the joint.
2. A process according to Claim 1 comprising the step of: removing any electrical contact between the adjacent metal rail sections, before, applying, in-situ, a curable insulating material into a gap between adjacent rail sections at the joint.
3. A process according to Claim 2 wherein the step of removing any electrical contact between the adjacent rail sections comprises the step of removing any conductive material bridging the gap between rail sections.
4. A process according to Claim 3 wherein the electrical contact between the adjacent rail sections is provided by metal from one or more rails bridging the gap between rail sections and comprising the step of removing sufficient amounts of rail material to remove the bridging and to form a gap suitable for applying, in-situ, into said gap a curable insulating material.
5. A process according to Claim 4 further comprising the step of removing any debris in the gap between rail sections before applying the curable material. **S. * 25

* **
6. A process according to Claim 3 wherein the electrical contact between the adjacent rail sections is provided by debris bridging the gap between rail sections and *** comprising the step of removing sufficient amounts of said debris to remove said ** bridging. *.** S. * * S S S *
7. A process according to Claim 3 wherein the electrical contact between the adjacent rail sections is provided by metal from one or more rails bridging the gap between rail sections and debris bridging the gap between rail sections and comprising removing sufficient amounts of rail material and removing sufficient amounts of debris in the gap between rail sections to ensure no electrical contact is formed by the rail sections or any debris.
8. A process according to any preceding claim comprising the step of removing any pre-existing insulation material before applying the curable insulating material.
9. A process according to any preceding claim wherein the curable material is an adhesive material that bonds within the gap to the rail sections.
10. A process according to any one of Claims 3 to 8 comprising the step of removing any contaminants that may exist on the surfaces of the gap to be filled and which may interfere with curing of the curable material.
11. A process according to Claim 9 comprising the step of removing any contaminants that may exist on the surfaces of the gap to be filled and which may interfere with bonding of the curable material to the rail sections.
12. A process according to any preceding claim comprising applying at least sufficient curable material to fill the gap and optionally smoothing off any excess material so that the material is flush with at least the top surface of the rail sections.
13. A process according to any one of Claims 2 to 12 wherein the removal of the electrical contact is done utilising a cutting tool such as an angle grinder.

* . 25 I'S.

* **
14. The process according to any one of Claims 2 to 13 wherein a gap of 3 to 10 mm wide is opened up between the rail sections. *.*

S
15. The process according to any one of Claims 2 to 14 wherein a gap of I to 10cm **I.

r* :* deep is opened up between the rail sections.
16. The process as according to Claim 15 wherein the gap cut is about 4mm wide and about 5cm in depth.
17. The process according to any one of Claims 6 to 16 wherein debris is removed using a blast of air.
18. The process according to any one of claims ito 17 wherein the curable material is applied into the gap using a dispenser such as a dispensing gun.
19. The process according to any one of claims 1 to 18 wherein a mould, positioned at the joint shapes the curable material to the profile of the rail sections.
20. The process according to any one of Claims I to 19 wherein the curable material is an adhesive resin.
21. The process according to Claim 20 wherein the curable material is a two-part curable composition.
22. The process according to Claim 20 or Claim 21 wherein the curable material is a polyurethane-based material.
23. The process according to any one of Claims 1 to 21 wherein the curable insulating material is at least one of MS polymer; two-part polyurethanes; two-part epoxies; two-part silicones; two-part acrylics; UV curable acrylics; UV curable epoxies.
24. A process according to any preceding claim wherein the curable material is applied *::::* 25 in-situ to a laid railway track. * **
25. An insulated rail-joint formed by the process of any one of Claims Ito 24. *** *

*.
26. A rail track incorporating an insulated rail-joint according to Claim 25. **.. ** ** * * * * *
27. Use of a material selected from: at least one of MS polymer; two-part polyurethanes; two-part epoxies; two-part silicones; two-part acrylics; UV curable acrylics; UV curable epoxies, for example two-part Teromix, as a curable insulating material for applying into a gap between adjacent rail sections. a. * *.. S... * . * I. * S S S.. *

S *S.

S 55S* * S *.S. *S 55 * S S * S