Bullhead rail

[Philip]

Why is bullhead rail not used for mainline track relaying anymore? Is it noisier than the modern rail used now and also can it take the same speeds?

 

[The Lad]

Fb is stiffer and can be welded into long lengths

 

[ElectroSoldier]

Why is bullhead rail not used for mainline track relaying anymore? Is it noisier than the modern rail used now and also can it take the same speeds?

Flat bottom rail is better, its stronger and allows higher speeds on curves, its cheaper to make and easier to lay it because it can and is delivered on site as a single piece. And the rail head keeps its profile longer too.

 

[furnessvale]

Fb is stiffer and can be welded into long lengths

There is nothing to stop BH being welded into longer lengths, but BH has so many deficiencies compared to FB for intensive main line use, why would anyone bother?

 

[edwin_m]

There is nothing to stop BH being welded into longer lengths, but BH has so many deficiencies compared to FB for intensive main line use, why would anyone bother?

I think the narrower cross-section of bullhead would make it more likely to buckle sideways if in compression, so it's unlikely that it would be able to withstand the same temperature range as flat-bottom rail if continuously welded.

 

[furnessvale]

I think the narrower cross-section of bullhead would make it more likely to buckle sideways if in compression, so it's unlikely that it would be able to withstand the same temperature range as flat-bottom rail if continuously welded.

Exactly. Just one of the deficiencies I alluded to.

 

[Dunfanaghy Rd]

I imagine bullhead rail is also more expensive, as there is no export market to spread the cost of new rolls, &c.
Pat

 

[Ploughman]

The increased mechanical handling of Concrete sleepers for FB rail is not possible to the same extent with BH versions.

As for the rail itself.
Theoretically it is possible to stress BH CWR but in practice it s very awkward to do.

 

[DaleCooper]

Would I be right in thinking that FB rail is better for spreading impact loads over a greater area?

 

[furnessvale]

More deficiencies of BH being posted.

I'll add, the smaller footprint of BH reduces the contact area and chair gall occurs deeper and faster.

 

[Sprinter107]

There is nothing to stop BH being welded into longer lengths, but BH has so many deficiencies compared to FB for intensive main line use, why would anyone bother?

Theres a good stretch of long welded bullhead rail between Colwall and Ledbury

 

[Bald Rick]

Bullhead rail is also significantly more costly to maintain.

 

[Philip]

Theres a good stretch of long welded bullhead rail between Colwall and Ledbury

Is this stretch significantly louder than on normal FB rail? What is the speed limit on this section?

 

[AndrewE]

Is this stretch significantly louder than on normal FB rail? What is the speed limit on this section?

That sounds like a good excuse for a day trip just to find out (and before it gets changed too.) For the speed limit, the sectional Appendices are available online, but unfortunately they are huge pdf files and not very easily navigated either.

 

[Sprinter107]

Is this stretch significantly louder than on normal FB rail? What is the speed limit on this section?

Not significantly louder, or rougher. Speed is 70mph.

 

[Sprinter107]

Its quite a straight section of track.

 

[ElectroSoldier]

There is nothing to stop BH being welded into longer lengths, but BH has so many deficiencies compared to FB for intensive main line use, why would anyone bother?

What are they?
You alluded to them but Im sure we would all like to know all of the actual real world in use differences between them.

 

[Bald Rick]

What are they?
You alluded to them but Im sure we would all like to know all of the actual real world in use differences between them.

Summarising the above, bull head compared to FB:

More costly to buy as a track system
More difficult, and thus more costly to install
More costly to maintain
More prone to buckling
More prone to in-rail defects and breaks
Smaller contact patch, thereby causing higher wear and shorter life

But otherwise it has loads going for it!

 

[YorksDMU]

There’s another section of welded bullhead rail between Cottingham and Beverley Parks, on the down line. It, however, is quite rough and noisy. It could really do with relaying with FB.

 

[furnessvale]

There’s another section of welded bullhead rail between Cottingham and Beverley Parks, on the down line. It, however, is quite rough and noisy. It could really do with relaying with FB.

I presume both the welded BH sections mentioned above have regular expansion joints rather than any attempt at destressing as done with FB?

 

[Joseph_Locke]

BH is only expensive to buy because the market is so small it isn't worth big regular rolling runs.

Relaying in FB isn't automatically better, but on NR lines will allow the conversion from jointed to CWR.

 

[Ploughman]

There’s another section of welded bullhead rail between Cottingham and Beverley Parks, on the down line. It, however, is quite rough and noisy. It could really do with relaying with FB.

If I recall rightly, that stretch was worked on back in late 90's and was upgraded from jtd to Lightweight CWR mainly by cropping out the bolt holes, stressing and welding up.
I don't think any resleepering or relaying of any type took place.