London Transport RT - RT4325 History

by Derek Funnell

Back in the early 1970’s, a friend of mine, Robin Thomas, told me that he was considering purchasing a London bus, and wondered if I’d like to go in with him. As I’d been interested in commercial vehicles since primary school days, I said yes.

He’d looked into the legalities of owning such a vehicle, and in those days it could be registered as a ‘private heavy motor car’ and driven on a car licence. He’d also arranged garaging for it. Insurance was a bit steep, and we could only carry a maximum of six persons.

He had seen RT4325 when it was still in use with London Transport (circa 1973), and had written to them to state his interest and ask when it was likely to be withdrawn from service. I don’t recall the response, but it was sold to the London Bus Preservation Group in November 1973, and he purchased it from them in October 1974 (RT4325 was the last RT in service that had a roofbox to display the route number).

These three photo’s show it in service, and were passed onto us by a bus enthusiast, following an article in the Hayes Gazette after Robin had bought the bus.

A couple of photographs of RT4325 in service can be found on the Internet: (At Kenton Road - circa 1968) & (At Golders Green Station - circa 1968)

We took it to a couple of rallies in 1975, and in February 1976 it was put in a barn on a farm in High Wycombe in order that renovation work could be carried out. At this point another person, Jeff Guy, became involved in the project.

And here is RT4325 at the Weymouth Rally in 1975.

We started by removing the lower body panels to make access to the chassis easier. As the panels came off, corrosion and wood rot were exposed, and therefore more panelling was removed. This was the thin end of the wedge, and we went on to dismantle both the body and chassis entirely.

The platform riser was removed in January 1978 as it was considered beyond repair, so a replacement was made with the aid of the LT drawings (RT.006.E1). Also the wheel arches and much of the rear partition.

These three photo’s show the body as it existed in 1980. All components here have been removed, refurbished and re-assembled.

Hot Riveting on the Frame 05 Apr 1981 & the frame assembly.  This shows how far the chassis was dismantled. The flitch plates are being riveted back onto the side rails.

The chassis has since been re-built, and was put on display at Covent Garden in on August 6th 1989 for the ‘RT50’ rally, and at Newark in May 2012 for the AEC centenary rally.

Work on the body suffered delays from other vehicular distractions, and for a while, existed as a lower deck skeleton, from the platform riser forward, but excluding the front bulkhead. 

The front bulkhead required much repair work to the lower panelling due to fatigue cracks and corrosion. LT fitted reinforcement panels at major overhaul. (See drawing RT.440.E1).

Here is an inter-roof panel for RT4325 shown after de-rusting. In the second image a PRV inspection stamp can be seen showing PRV 15 (Did "15" denote a particular inspector?  Does anyone know? Ed.).

Derek Funnell's update - January 2016 

Derek writes: "Here’s a rather overdue update on RT4325’s restoration progress.  The main milestone passed, is the rebuilding and fitting of the front bulkhead. Work on the bulkhead began in August 2010 and was completed in November 2014.  With that installed, it was then on to the floor framework, and those in number 1 & 2 bays have now been fitted."

Front Bulkhead

RT Bulkhead 03/Oct/2010

Bulkhead components 26/Aug/2012

Front bulkhead in progress 13/Jan/2013

Panel assembly located on bulkhead 11/Aug/2013

Preparing to rivet top panel to bulkhead centre column 13/July/2014

Riveting channel section to bulkhead 28/Sep/2014

Fitting roof stick to bulkhead assembly 26/Oct/2014

Fitting timber packing to bulkhead pillar channel 26/Oct/2014

Applying Celloseal (Jointing compound) to bulkhead roof stick 02/Nov/2014

Front bulkhead assembly 09/Nov/2014

Derek, Verdun, and Jeff moving front bulkhead assembly 16/Nov/2014

Front bulkhead assembly about to be installed 16/Nov/2014

Fitting front bulkhead 16/Nov/2014

Front bulkhead assembly refitted to body framework 16/Nov/2014

Front bulkhead 20/Dec/2015

Bottom Frame

Coving panels - No. 1 bay - inside 30/Nov/2014

Floor frame assembly - No. 1 bay 30/Nov/2014

New coving rail for No. 1 bay O/S 27/Dec/2014

Riveting coving panel 23/Jan/2015

Rivet dolly for coving panel assembly 01/Mar/2015

Riveting coving panel assembly to foot bracket 01/Mar/2015

Coving panel assembly installed 12/Mar/2015

Fitting timber to No. 1 bay floor framework 22/Jul/2015

Floor frame assembly fitted - No. 1 bay 09/Aug/2015

Fuel filler coving panel assembly 23/Aug/2015

Floor frame assembly No. 2 bay 20/Sep/2015

Fuel filler coving panel - Initial assembly 22/Oct/2015

Fuel filler coving panel assembly - Preparing for riveting 23/Oct/2015

Fuel filler coving panel assembly - Riveting 23/Oct/2015

Fitting timber to No. 2 bay floor frame 18/Dec/2015

Fitting floor frame assembly - No. 2 bay 03/Jan/2016

Derek Funnell's update - July 2017 

Derek writes: Fitting of the lower deck floor framework was completed in June 2016. New footstool floor panels were made up and fitted in No. 3 bay in July 2016. These had to be made in two pieces and butt welded, due to the semi-circular pressing not running the entire length of the panels; to have made them as one piece panels would have required some serious press tooling!  We were very happy with the finished result.

The next task was to make up and fit new cant plate sections along the edge of the inter roof. The original ones were beyond repair, so we had eight foot long sections (longest we could get) made up by a local sheet metal fabricator.  Between August & September 2016 the sections were cut, drilled, and welded, to make the four cant plate assemblies (as per LT drawings RT.002.G9, RT.046.G1, & RT.055/6.G1).

The new cant plates could have been fitted at this stage, but it was preferable to fit them with the foot brackets as they are bolted through the cant plates and effectively secure them to the inter roof sticks.  As it was a wet assembly (jointing compound) we wanted all fixing points to be fully secured on installation.

Like the cant plates, the original foot brackets were also beyond saving, so a complete new set was made up; including the various items of tooling required (formers, press tools, drill jigs).  Manufacturing the brackets took about three months (Jan – Mar 2017).

With the foot brackets completed, installation of the cant plates was carried out during April and May 2017.
The next item on the agenda is the front frame assembly; and that will figure in the next progress update.

Bottom Frame

RT floor framework 26/June/2016 
(both old and new cant plate sections can be seen on the floor in this photograph)

Footstool floor panel test pieces; made June/2016

Forming footstool panels 19/June/2016

Footstool floor panels 30/July/2016

O/S footstool floor panel 11/September/2016

Foot Brackets

Machining RT foot bracket former 19/January/2017

Forming RT foot bracket blank 10/February/2017

Flanging holes in foot bracket side plates 05/March/2017

Foot bracket side plates 07/March/2017

Spot welding foot brackets 09/March/2017
(a genuine original unused foot bracket can be seen in the background of this photo’ - only one we had)

Drilling bolt holes in foot bracket 31/March/2017

Completed foot brackets 13/April/2017

Inter Roof

Cant plate welding fixture 17/Aug/2016

Welding NS rear cant plate section 10/November/2016

Applying jointing compound to O.S. front cant plate section 23/April/2017

Fixing O.S. foot bracket at bulkhead stick 23/April/2017

Riveting offside rear cant plate 25/May/2017

Nearside cant plate 09/June/2017

Offside cant plate 09/June/2017

 

The following chart shows, in practice, the result of the Works Float System employed at London Transport's Chiswick and Aldenham works where chassis & bodies were exchanged on a regular basis.  For a more comprehensive understanding of this process see London Transport Aldenham Works. Ed.
RT4325 (Reg. No. NLE 989) History

AEC Chassis No. 09617290 

Park Royal Body No. 2103 History

AEC Chassis No. 09617290  (LT CU5229) (see Note-1)

Fitted to AEC chassis No. 09611055 (LT CU1890)

Reg. No. NLE 989 [Log Book references chassis 09617290] 

Reg. No. JXN 202

Initial body No. 8374

Body No. 2103

First registered 15/06/53

First registered 08/04/48

Type: 3RT8/2 (although at some time it was re-designated 3RT10, possibly when body No 2103 was fitted).

Type: RT3(c) RT824 (Built in a batch designated RT752 to RT851).

First in service 15/07/53 at Victoria, although between those dates it is listed as being at Park Royal and Aldenham.

First in service 22/09/48 at Mortlake, although between those two dates it is listed as being at Aldenham, Park Royal and Chiswick.

This AEC chassis 09617290 (LT CU5229) was given a Saunders bodied RT 250 and was scrapped in 1970!

Body removed from RT824 23/02/56. Transferred to RT925, JXN303.

Removed from RT925 28/09/59. Transferred to RT2774 LYR758.

RT824 scrapped at Wombwell Diesels 22/05/73 with Body No. 5833.

Re-bodied 28/01/64 with Park Royal body No 2103.

Removed from RT2774 28/01/64. Transferred to RT4325.

Converted to Decimalisation Trainer 10/09/70 at Leyton.

In storage from 01/04/71 to 15/10/71.
Used for driver training between 16/11/71 and 09/11/73.
Sold to London Bus Preservation Group, Cobham 12/11/73.
Purchased by Robin Thomas 20/10/74.
I am grateful to Brian Watkinson for the details below on the pre-history of this chassis & body combination

AEC Chassis No. 09611055 - RT4325 PRE-history

Park Royal Body No. 2103 Type RT3 PRE-history

The AEC chassis number is actually irrelevant; LT gave this chassis the designation CU1890 (Chassis Unit) in 1948. 

New as RT 824: 22/9/48 to M 26/7/50 J 12/9/52 to Aldenham (WK) for overhaul 

New as RT 1053 19/12/48 to GY 12/12/48; 26/1/53 WK for overhaul. (Chassis overhauled at Chiswick)

O/H Still RT 824 24/9/52 to J 16/7/53 HW 9/55

O/H Still RT 1053 26/2/53 to GY 28/8/56 WK for overhaul

Body type reclassified as RT 10 (see Note-2) 23/2/56 WK for overhaul.  

Now RT 1141 18/12/60 to RD 20/1/64 WK for overhaul

O/H Now RT 925 21/3/56 to HW 24/9/59 WK for overhaul.

O/H now RT 4325 to AP 19/2/64 with body No. 2103 (See body details right).

O/H Now RT 2774 21/10/59 to HD 17/1/64 WK for overhaul.

O/H now RT 4325 to AP 19/2/64 23/5/67 WK re-paint 3/1/5/67 AE 24/7/70.

Delicensed (u) at AE 10/9/70 T Decimal trainer 1/4/71 Tu 19/10/71 CTu 16/11/71 H Trainer (t) 12/8/72 Dt 9/11/73 Du Sold 22/11/73

Note-1: For any vehicle undergoing overhaul at Aldenham (and Chiswick too) its body & chassis were often (usually) interchanged with bodies & chassis of other similar vehicles; that resulted in Registration Plates (and thus Log Books) being applied to a body/chassis combination that was not the original.  The Log Book & Tax Disc being Department of Transport official documents cannot ever be altered, thus a Tax Disc referencing a particular Registration Plate would always reference the original Chassis for that vehicle.  In order that a bus could leave Aldenham the same day as one with the same LT designation number & Registration Plate came in for overhaul (and the Tax Disc swapped over), it was necessary that the actual chassis could be changed.  Although LT had governmental dispensation to transfer registration numbers between vehicles, as the Log Books could not be altered, LT gave each chassis a unique Chassis Unit (CU) number in order to know which was which (for more information see the Aldenham page).

In the case of RT4325 (NLE 989), it finally left Aldenham with body 2103 & Chassis CU1890 (that was AEC Chassis No. 09611055).  However, on the brass plate on the dumb iron it had RT4325 & AEC Chassis No. 09617290, that tied up with the Log Book for NLE 989 (and the stock number RT4325) but was not the actual chassis in use.

The original chassis 09617290 for NLE 989, that was given LT CU5229 designation, ended up on a Saunders bodied RT 250 and was scrapped in 1970! 

Note-2: 150 bodies that were delivered in 1948 and fitted to RTs 752-851 and 962-1011 incorporated a number of modifications. These included the fitment of body mountings that would enable the body to fit the Leyland RTL chassis. The cab front, the front N/S and front bulkhead were modified to the same design as that of the Saunders RT3/3 body with a route plate holder fitted under the canopy, semaphore signal castings fitted on the N/S front bulkhead pillar, and on the O/S below the cab entrance, the rear registration plate box was also redesigned to incorporate a direction arrow. The front N/S canopy valence panel was cut away to allow the route plate to be seen (in the same style as all later RT bodies that had the canopy blind box fitted). The cab front lower rail (below the headlight) was altered to sweep up over the larger O/S chassis dumb irons of the RTL chassis ( the RT10 body's cab lower front rail was NOT the same as the Saunders; as with the RT3 the Saunders bodies were NOT intended to be fitted to RTL chassis and had no need of the cab front bottom rail sweeping above the dumb irons).  This design was applied to all later RT bodies. Although originally classified as RT3 bodies these bodies were reclassified as RT10 in September 1955.

I am grateful to Derek Funnell for supplying the set of over eighty documents of drawings, plans, lists etc. detailing the London Transport RT body structure that was used in the reconstruction of RT4325. These documents can be downloaded from the LT RT Downloads page. Ed.