CIE Tar Bitumen Tanks – the 1950s/60s wagons

[Mol_PMB]

Historical background

Tar and bitumen are hydrocarbons, very heavy dense fractions which are almost solid at ambient temperatures. They are widely used in road surfacing, combined with stone chippings to produce Tarmacadam / Asphalt.

In Ireland, tar/bitumen was primarily transported in barrels or drums until the 1950s. After the emergency years, there was a major boom in road transport. Many Irish roads were unsuitable for the increased speeds and tonnage of traffic, and so a programme of roadbuilding and improvements was undertaken. This required much larger quantities of tar/bitumen, as well as stone chippings. CIE was responsible for transporting both commodities – the stone was mostly transported by road from local quarries, but the tar/bitumen was imported to North Wall and distributed by rail. To cater for the increased quantities, a fleet of tank wagons was introduced – bulk transport being more efficient than handling thousands of barrels.

CIE’s annual reports from the period often refer to this traffic, which seemed to be increasing consistently even in the context of declining freight overall. A summary of the main references may be of interest:

• 1952: The second development is the bulk movement of tar and bitumen, in gradual substitution for the former system of conveyance of these commodities in drums. The Board has commenced a building programme of rail and road tankers to enable hot bitumen and tar to be conveyed in bulk and the first of these units was introduced during the year. The economies achieved by this bulk transit system, as compared with the former, are apparent and the Board is taking all steps to secure as much as possible of this traffic.
• 1953: The development of tar and bitumen traffic in bulk is of recent origin and the basis of this traffic is that of bulk deliveries to storage plants erected by County Councils at various points in their areas from which distribution is made by the County Councils’ road repair vehicles. The Board makes every endeavour to facilitate the County Councils by the provision of sites for erection of storage plants. An additional 33 rail tar tankers and 8 road tar tankers were provided for the transport of hot bitumen.
• 1954: Goods traffic showed an increase over the previous year, particularly in the carriage of … tar and bitumen. … Seventeen new rail tar tankers were put into service, making a total of 50 in operation during the year. These vehicles, with a total capacity of 83,000 gallons, were fully taxed in dealing with the traffic offering.
• 1955: During the year, 30 additional rail tankers were put into service for the tar and bitumen bulk traffic, bringing the total number in operation to 80.
• 1956: Revenue from the bulk carriage of tar and bitumen increased by approximately £20,000 compared to the previous year and the demand for bulk service continued to increase. During the year, 28 rail tank cars of 1,200 gallon capacity each, were increased to 3,000 gallon capacity.
• 1957: Tar and bitumen carried – 48,474 tons – was an increase of over 9,000 tons compared with the previous year owing to an increase in road work coupled with a higher demand for delivery of this material in bulk.
• 1958: Ten open goods wagons were converted to tar and bitumen tankers, bringing the total number of vehicles for this traffic to 90.
• 1959: The carriage of tar and bitumen in bulk amounted to 51,340 tons, or an increase of 4,957 on the previous year’s figures. This rise was due to the increasing number of County Councils which are taking delivery of road dressing materials in bulk. For this traffic Coras Iompair Eireann operates a fleet of 90 special bulk tar tankers.
• From 1961, ‘Tar and Bitumen in bulk’ had become significant enough to be listed separately in the traffic statistics, and the annual tonnage continued to rise, as shown by these figures for 1961 and 1962:

Traffic

The tar/bitumen traffic seems to have mostly originated at North Wall, having been imported by ship. Photographs indicate that small numbers of tar/bitumen wagons were delivered by mixed goods trains to goods yards or private sidings all across the network. In the 1950s and 1960s the customer was usually the local county council, but later private firms became involved and these included Roadbinder Ltd, Cold Chon and Esso.

Examples of locations receiving tar/bitumen traffic in included Lixnaw, Tralee, Killarney, Quartertown (Mallow), Sligo Quay, Roscrea, Oranmore, Cahir Abbey, and no doubt many other places across the country.

[Mol_PMB]

I should acknowledge this earlier thread on CIE tar wagons, which focused on the later vacuum-braked wagons but did also include some useful info on their predecessors:

 

The Wagons - Overview

In this thread I am going to focus on the wagons built in the 1950s and 1960s, such as this example:

(photo provided by John Mayne in the thread linked above)

At first glance the tar/bitumen tank wagons look like many other traditional 4-wheel hand-braked tank wagons. A cylindrical tank on a skeleton chassis, with ladders leading up to filler at the top, and a discharge valve underneath. They were black, and when new had bold ‘TAR BITUMEN’ branding in white on the sides and ends. This soon got covered in tar spillage. Most of the CIE tar/bitumen tank wagons were of the anchor-mounted type, a technology which was approved in the 1940s.

It was common practice in GB for hydrocarbon tank wagons to be privately owned; this was also the case in Ireland where firms such as Esso, Irish Shell and Burmah had their own fleets of oil tank wagons. But the tar/bitumen traffic carried by CIE was primarily for local council road improvements, so it must have made more sense for CIE to own the tank wagons.

Tar/bitumen is solid at ambient temperatures, so it had to be heated to enable the wagons to be loaded and unloaded. To help keep the contents liquid on their journey, the tank barrels were lagged with insulation, and the lagging was covered with thin cladding, giving the outside of the tanks a square-cornered look rather than having domed ends (the vessel inside was domed). To enable tar wagons to be emptied if the load has cooled, the tanks were usually fitted with some internal pipes through which steam could be passed. This would warm and liquify the load. The style and positioning of these steam fittings could vary between batches of wagons.

 

In ‘Irish Railways Today’ (Pender & Richards, 1967) they list the tar bitumen wagons constructed by CIE, as follows:

• 23801-23830, built 1953, 15 ton capacity, 17’6” length over headstocks
• 23831-23845, built 1953, 15 ton capacity, 17’6” length over headstocks
• 23851-23870, built 1954, 15 ton capacity, 17’6” length over headstocks, built by Charles Roberts, 3062 gallon capacity
• 23871-23890, built 1954, 15 ton capacity, 17’6” length over headstocks
• 25001-25020, built 1962, 15 ton capacity, 17’6” length over headstocks, built by Charles Roberts, 3190 gallon capacity

‘A number of wagons have been built for the tar and bitumen traffic which originates at the North Wall depot. Forty of these have been built by Charles Roberts Ltd and the rest by CIE.’

Pender & Richards generally focus on new construction and do not include wagons inherited from the GSR, nor do they describe all conversions. The list above indicates a total of 85 wagons built in 1953/54, and a further 20 in 1962.

The CIE annual reports tell a slightly different and more complex story:

• 1953: 33 rail tar tanks introduced
• 1954: 17 rail tar tanks introduced, total now 50 with a total capacity of 83,000 gallons [an average capacity of 1,660 gallons per tank, but they probably weren’t all the same]
• 1955: 30 rail tar tanks introduced, total now 80
• 1956: 28 rail tar tanks rebuilt from 1,200 to 3,000 gallon capacity
• 1958: 10 rail tar tanks converted from former open wagons, total now 90
• 1962/3: the final batch is not mentioned, but this may be a consequence of the revised style of annual reports in the 1960s  

I’m going to try and make sense of this by reference to photos, but it’s a challenge!

[Flying Snail]

I have to say, these threads you're creating are great resources. There's clearly a lot of research going into them!

[Mol_PMB]

Two batches of the tar/bitumen tank wagons were built for CIE by Charles Roberts, a well-established firm in Wakefield with particular expertise in tank wagons.  The Charles Roberts records still exist in the care of the HMRS, and the archive of official works photos is available online. These wagons are also detailed in the CIE 1972 wagon register (of which Michael mfjoc has a copy).

Consequently, there is generally more technical information available on the Charles Roberts wagons than the ones built or converted by CIE themselves.

From the HMRS archive, this is a works photo of 23855 at the Charles Roberts factory on 23rd March 1954:

 

This was one of the batch described by Pender & Richards as:

• 23851-23870, built 1954, 15 ton capacity, 17’6” length over headstocks, built by Charles Roberts, 3062 gallon capacity

Considering the publication dates of the CIE annual reports, this batch of 20 probably missed the 1954 report and would be included in the 30 new tar tanks reported in the 1955 report.

 

Some features to note in the photo above:

• GB RCH-style underframe, 10'0" wheelbase, BR-style plate axleguards with a circular hole in.
• Tie-bar connecting the axleguards.
• GB style brakes - independent brake each side operating brake shoes on both wheelsets.
• Tank (including lagging) is slightly longer than the 17'6" underframe.
• Tank secured by anchor mount arrangement with the cradles inboard of the wheels.
• Steam pipe fitting on the side of the tank (just left of the 'not to be loose shunted' lettering)
• There is also a note about air pressure - these tanks were fitted with an air connection to enable the tank to be pressurised slightly to encourage the thick tar to discharge.

The tar/bitumen tank wagon diagram shown in CIE's 1972 diagram book is of this type. Many thanks to @mfjoc for a copy of this, which is extremely useful in giving the overall dimensions:

Note that both batches of wagons built by Charles Roberts are listed on this diagram.

The 1962 batch were similar, but not identical, as I'll show in the next post.

Edited Thursday at 11:35 by Mol_PMB
better image link

[Mol_PMB]

The other batch of tar/bitumen tanks built by Charles Roberts was completed in 1962, and is illustrated by a pair of photos in the HMRS photo archive.

Here's 25018 on 16th July 1962, showing the side with the steam fitting (left hand end of the tank).

And here's the opposite side of 25002 on 31st May 1962, without the steam fitting. Note also the manhole and ladder are offset towards one end of the tank. 

These two were from the batch described by Pender & Richards as:

• 25001-25020, built 1962, 15 ton capacity, 17’6” length over headstocks, built by Charles Roberts, 3190 gallon capacity

Compared to the previous batch 23851-23870, the major difference is that the tank support cradles have been moved further apart, and are directly above the wheelsets.

These views also show that this final batch had the outer tank cladding slightly longer than the end cladding, so there's a 'flange' visible around the ends of the tanks. 

 

As shown in the previous post, the wagon diagram book entry has just one diagram covering these two batches, and the associated technical data is here:

 

Note that the precise capacity depends on the condition of the load, and there is allowance for thermal expansion when it is heated for discharge. The absolute tank capacity is given as 3,190 gallons but lower values of 3,142 or 3,062 are also quoted which may be the usable capacity. This sheet also shows the load capacity as 14.5 tons whereas other sources give 15 tons. We probably shouldn't get too hung up about the 'exact' capacity (whether in gallons or tons) since it depends on the temperature and density of the load. In round figures all these Charles Roberts wagons are 3,000 gallon, 15 ton tanks.

[Mol_PMB]

Having dealt with the relatively simple Charles Roberts tar tanks, let's move on to the first of the CIE-built batches, which according to Pender & Richards were:

• 23801-23830, built 1953, 15 ton capacity, 17’6” length over headstocks

Statements from the CIE annual reports that may be relevant to these wagons include: [my comments in square brackets]

• 1952: The Board has commenced a building programme of rail and road tankers... [but only one, probably a road tanker, completed in this year]
• 1953: An additional 33 rail tar tankers and 8 road tar tankers were provided for the transport of hot bitumen.
• 1954: Seventeen new rail tar tankers were put into service, making a total of 50 in operation during the year. These vehicles, with a total capacity of 83,000 gallons [an average capacity of 1,660 gallons per tank]
• 1955: During the year, 30 additional rail tankers were put into service for the tar and bitumen bulk traffic, bringing the total number in operation to 80. [20 of these new tanks were by Charles Roberts]
• 1956: During the year, 28 rail tank cars of 1,200 gallon capacity each, were increased to 3,000 gallon capacity.

These statements indicate that 50 tar tanks were built in 1953/4, and that the majority of them were of quite small capacity (fleet average 1,660 gallons - for example this could have been made up of 30 tanks of 1,200 gallons and the remaining 20 being 2,400 gallons). The rapidly growing traffic and the example of the 3,000 gallon Charles Roberts tanks may then have encouraged CIE to rebuild the smaller tanks to 3,000 gallons, when they were only 2-3 years old.

So, one interpretation of this information is that the 30 wagons 23801-23830 were built in 1953 with small 1,200 gallon tanks, and were rebuilt with 3,000 gallon tanks in 1956. There are other possible interpretations of course. 

What is clear from photos is that this batch of 30 wagons were latterly quite consistent, and had large tanks similar in size and style to the Charles Roberts tanks. It is quite plausible that they were of the same nominal 3,000 gallon, 15 ton capacity and the tanks themselves may even have been supplied by Charles Roberts. However, the underframes were different and had distinctive Irish features.

This photo from Ernie is dated 19th June 1956, and shows 23829 looking reasonably clean and fresh:

This IRRS image is an excellent portrait of 23805 dated September 1964, with a recent repair to the cladding on the end of its tank. It appears to have a steam heating pipe below the headstock (as used for train heating) which may have been connected to the coils in the tank.

https://www.flickr.com/photos/irishrailwayarchive/54251527038

@Mayner's photo of 23826 in the 1970s shows one of these tanks towards the end of its life:

Some features to note in the photo above:

• Plate axleguards with no holes in (unlike BR type on the Charles Roberts tanks).
• Absence of tie-bar connecting the axleguards (present on the Charles Roberts tanks).
• Irish style brakes - long brake handle operating a single brake shoe on the left-hand wheel.
• Tank (including lagging) is slightly shorter than the underframe.
• Tank secured by anchor mount arrangement with the cradles inboard of the wheels (same as the first batch of Charles Roberts tanks).
• Steam pipe fitting on one end of the tank (rather than on one side)
• The ladders are in line with the end of the catwalk (rather than the middle)
• Later in life, a raised plate was provided on the tank side for the 'Tar Bitumen' lettering, so that tar spills would not conceal the branding.

This IRRS photo dated 11 June 1958 gives a useful top view of three of these tanks: 

https://www.flickr.com/photos/irishrailwayarchive/53500839366

Two IRRS photos at Inchicore in early 1964 show a couple more of these wagons:

https://www.flickr.com/photos/irishrailwayarchive/53505734117

https://www.flickr.com/photos/irishrailwayarchive/54251291181

From Ernie, a short rake of these tanks being shunted at Cork:

Another view of 23826, at Tralee on 3 May 1978. Photo by Gerry McMahon published in IRRS Journal 186 but not available online. Note the steam pipe connections on the end of the tank:

 

Edited Thursday at 14:15 by Mol_PMB
extra photo

[Mol_PMB]

What of the remainder? This gets even more confusing. 

The batches listed by Pender & Richards that are not yet accounted for are:

• 23831-23845, built 1953, 15 ton capacity, 17’6” length over headstocks (total 15)
• 23871-23890, built 1954, 15 ton capacity, 17’6” length over headstocks (total 20)

The batches listed by the CIE annual reports that are not yet accounted for are:

• 1953/4: 20 rail tar tanks introduced, [thought to be medium/large capacity 2,000 to 3,000 gallons] (plus 23801-23830 already accounted for)
• 1955: 10 rail tar tanks introduced (plus 23851-23870 Charles Roberts already accounted for)
• 1958: 10 rail tar tanks converted from former open wagons

These two lists contain different total quantities of wagons and build dates. They are difficult to reconcile.

Let's look at the available photos of tar tank wagon batches not yet described. 

First, the CIE wagon diagram book listing for the Charles Roberts built tanks is illustrated by this photo of 23832 (which was NOT a Charles Roberts built wagon):

This has an 'Irish' underframe, but is different from the 23801-23830 series because the tank is a fair bit shorter than the underframe. I think the underframe is standard length so the tank is shorter. It might also have a slightly smaller diameter, which would make it closer to 2,000 gallons than the later standard 3,000 gallons capacity.

This IRRS photo is by Norman McAdams and was published in IRRS journal 198 but isn't available on the Flickr archive. It shows 23845. My impression is that it also has a shorter tank like 23832 above, but I admit it's very hard to tell from this angle. It has an 'Irish' underframe and brake arrangement.

Incidentally this photo puts the very minimal tar discharge facilities into context:

https://www.flickr.com/photos/irishrailwayarchive/54256975193

So I would tentatively suggest that the batch of 15 wagons 23831-23845 were built with medium capacity tanks (around 2,000 to 2,500 gallons) and retained those tanks throughout their life.

(Remember that their predecessors 23801-23830 appear to have been built with 1,200 gallon tanks and then rebuilt with 3,000 gallon tanks)

 

This undated photo from Ernie shows lots of tank wagons, though they may not all be Tar/bitumen tanks.

 Zooming in we can make out 23871 on the left. This may be one of the tanks described as converted from open wagons, and might have had a different length underframe and/or tank. From this angle, we can only guess!

 

Another mystery is the tank in the background of Ernie's super photo at Nenagh on 6th June 1961:

Zooming in, this is definitely a tar bitumen tank but it is structurally very different from the ones we've looked at so far. This isn't an anchor-mounted tank but uses the older saddle-mounting arrangement with end stanchions and diagonal tie bars. It's unlikely that a tank of this type would have been built new in the 1950s, so this may be an older vehicle modified for tar bitumen traffic. My best guess at the number is 25437, but I'm not confident of that. I am pretty sure that the middle digit isn't an 8, so this is numbered in a different series to the other tar/bitumen tanks.

I'll keep searching for more photos and would be delighted if anyone can point me in the right direction or share their examples on this thread.

 

I've also got a couple of posts to come about modelling some of these. 

Edited Thursday at 15:24 by Mol_PMB
correcting typo

[Mol_PMB]

Some more photos found. Two excellent images of the last batch of Charles Roberts tanks after delivery to Ireland, but still brand new. Here are 25008 and 25009 in July 1962, showing the steam heating pipe connections and the unloading pipe too:

https://catalogue.nli.ie/Record/vtls000306097

https://catalogue.nli.ie/Record/vtls000306096

Here's 23868 of the first Charles Roberts batch, at Inchicore in January 1956 looking a bit grubby:

https://www.flickr.com/photos/irishrailwayarchive/54253400540/

JHB's book 'Rails Through North Kerry' has a nice sequence of images of 23855 being shunted at Lixnaw on 12th November 1976. This is the same wagon that was photographed by Charles Roberts when brand new, and seen upthread.

The same book also has a much earlier photo at Ballingrane, showing 23817 and another similar tank, looking very clean and newly painted.

[Mol_PMB]

Now, modelling. 

The best starting point is almost certainly the Bachmann anchor-mounted tank, which represents a Charles Roberts design very similar to those supplied to CIE in 1954 (23851-23870). This was made in black in Esso or Regent livery, and while the models are a few years old they aren't hard to find on EBay. A black one (class B) is a better starting point than a silver one (class A), as it has the right fittings for a tar tank including the steam heat connection on the tank side. 

The Bachmann tank diameter actually lies somewhere between the correct diameters for a 14T class B (6'7") and 14T class A/20T class B (7'3"). It's a compromise allowing the same moulding to be used for both. But for the CIE tar tanks it's perfect, because the diameter over the cladding of the tar tanks was 6'11.5" - matching the Bachmann model.

For an OO gauge model, the minimum job is to remove the existing lettering and add transfers to represent the CIE livery.

There are a couple of other discrepancies which could be addressed for a slightly more accurate model of the CIE Charles Roberts wagons:

• Reshape the tank ends to represent the cladding of a lagged tank 
• Add a tiebar between the axleguards
• Add the extra steam plumbing fitted to the Irish wagons
• Widen the frame by 2mm to represent a broad gauge wagon (especially if wanting 21mm gauge). This would also enable the saddle shapes to be modified to better match the Irish wagons.

Alternatively, the wagon can be modified to represent one of the Irish-built variants, with additional modifications to the brake gear instead of fitting the tie bar between the axleguards.

 

For the more determined, you can build a replacement super-detailed underframe using an etched kit from Rumney Models; the kit also includes some more finely detailed ladders:

https://website.rumneymodels.co.uk/tank-wagon-underframes

https://website.rumneymodels.co.uk/wp-content/uploads/2017/04/B.71_14T_Anchor_Mount_Tank_Wagon_Chassis_Instructions.pdf

This underframe kit would still need widening to suit 21mm gauge though!

 

 

Edited Thursday at 17:10 by Mol_PMB
correcting typo

[David Holman]

Splendid research!