Having addressed its urgent need for coal hoppers and container wagons, EWS (English, Welsh and Scottish Railways) placed an order for 68 bogie aggregate hoppers in 2005 ^[1]. The York works reopened by Thrall Europa for EWS's earlier orders had by then closed again, and consideration was given to constructing the new wagons at Thornaby Carriage and Wagon depot ^[2]. Instead the order went to Trinity Rail, with the wagons to be built at its Astra Vagoane plant in Romania ^[3]. Trinity had merged with Thrall in 2001, but the company was bought by IRS (International Railway Systems SA) in August 2006. A number range in the railway-owned series was allocated for the new wagons (320000-320067) along with TOPS code HOA and design code HO002A ^[4]. Design code HO001A had already been used in 1997/8 for a reduced-height conversion of a HEA hopper wagon ^[5], later rebodied as a standard HEA. Curiously, although the design code was not reused, the TOPS AARKND of HOA-A was.

The first of the HOAs were delivered in December 2006, carrying a livery of cream with two thin maroon stripes, EWS Construction lettering, and the 3 animal heads logo. The solebars and Axiom Rail TF25 bogies were grey, while the hopper ends were of the fully enclosed type. Their initial allocation was to Tarmac workings from Stud Farm Quarry to Hayes ^[6]. They were also used on sand trains from Acton to Marks Tey ^[7] and from Irvine (for WBB Minerals) ^[8].

Changes to the traffic and livery of the still-new wagons took place during 2007. In May a deal was reached which would see EWS take over ownership of the former RMC (Ready Mixed Conrete) JGA hoppers used from Peak Forest on workings for Cemex. The JGAs were to be partially replaced by 48 of the HOAs, which would be repainted into Cemex livery of white (upper half of the body) and blue (lower half). Repainting of the wagons was undertaken by Marcrofts at Stoke ^[9]. The other 20 HOAs were to remain on workings for Tarmac.

HOA liveries after 2007

3200xx	=Cemex white/blue		3200xx	=EWS Construction livery
320000	320010	320020	320030	320040	320050	320060
320001	320011	320021	320031	320041	320051	320061
320002	320012	320022	320032	320042	320052	320062
320003	320013	320023	320033	320043	320053	320063
320004	320014	320024	320034	320044	320054	320064
320005	320015	320025	320035	320045	320055	320065
320006	320016	320026	320036	320046	320056	320066
320007	320017	320027	320037	320047	320057	320067
320008	320018	320028	320038	320048	320058
320009	320019	320029	320039	320049	320059

In July 2007, EWS placed an order for 34 additional wagons for the Cemex traffic, although the contract went to Greenbrier instead of IRS ^[10]. Before the wagons were delivered the European Railway Agency issued its Technical Specifications for Interoperability. One result of this was that all new wagons were to be assigned numbers in the 'international' series. The new hoppers were thus numbered 33.70.6955.068-101, the last three digits forming a continuation of the HOA series. Deliveries started in August 2008 ^[11]. The design was quite different from the HOAs, being more akin to the Freightliner HHA/HXA and HIA hoppers also built by Wagony Swidnica in Poland. The Cemex-branded livery featured blue on the lower half of the hopper sides with light grey (or off-white) above. The solebars and TF25 bogies were grey.

The new standards also affected the coding of wagons. UIC type codes were to be applied to wagons, in this case Fabfnoos. The logic of the TOPS coding system seems to have been a bit thrown by the change of numbering. UK-registered railway-owned hoppers with international numbers would be expected to be coded HIA, although that code had already been used for Freightliner's aggregate wagons. Curiously, the new wagons were instead coded IIA-B, a code that would latterly have applied only to foreign-registered wagons. They were also given design codes in the international series (IIE937) ^[12].

Around the turn of 2008/2009, a decision was made to remove the Cemex branding from the HOA and IIA wagons, no doubt to simplify the allocation of wagons to the various traffic flows. The white/blue livery was retained ^[13]. Trains are often formed of a mixture of HOAs in both liveries and IIAs.

Built straight after the EWS IIAs was a batch of 40 similar hoppers ordered by wagon lessor Nacco in early 2008. These were originally to be divided between 20 for Mendip Rail and 20 for speculative use ^[14], but this was soon changed with all 40 being taken by Mendip Rail ^[15]. Delivered in September 2008, a greyish-silver livery was carried, with MRL (Mendip Rail Ltd) branding at the left-hand end and NACCO at the right ^[16]. The wagons were numbered as 37.70.6955.100-139 with TOPS code IIA-B, design code IIE940 ^[17] and UIC type code Fabfnoos. A curious aspect of this is the duplication of the numbers xx.70.6955.100 and xx.70.6955.101 from the preceding batch of IIAs. The first two digits (the exchange code) should not be part of the unique wagon identity, as they were liable to change. However, for these two pairs of wagons, the exchange code (and the check digit) is required to tell them apart.

A further batch of 20 hoppers for use by Mendip Rail was ordered by VTG in 2009, constructed once again at Greenbrier's Wagony Swidnica works in Poland. These carried the same silver livery but with the VTG logo at the right instead of NACCO. Intended to carry sea-dredged sand from Dagenham to Acton and elsewhere, the wagons featured modified interior linings and door seals but were otherwise identical to the earlier batch. They were allocated the same codes (IIA-B, IIE940, Fabfnoos) and were numbered to follow on as 37.70.6955.140-159 ^[18].

Delivery of this batch took place in August and September 2009, the wagons being first sent to Knights Rail Services at Eastleigh where they were given anti-corrosive interior paint ^[19]. The wagons entered service on the Dagenham workings, replacing PGA 4-wheel hoppers. In June 2010 the rake was briefly trialled on sand workings between Peteborough and Goole, covering for PAA hoppers taken out of use following corrosion problems ^[20]. At any one time, 6 of the 20 wagons are assigned to pool 212, being used to bolster the small fleet of Brett-branded JHA hoppers on workings between Cliffe and Tolworth ^[21].

The bright red livery of DB Schenker started appearing on the HOA fleet at the end of 2014, when 320054 was repainted by Axiom Rail at Stoke ^[22]. Further repaints took place in 2015.

More HOA hoppers were ordered in 2015 in two separate batches. French lessor Ermewa was to supply 53 of the type for use by Tarmac, while VTG would provide a quantity for Mendip Rail, the latter contract covering 130 wagons including both hoppers and open boxes ^[23]. Both batches were to built by Astra Rail in Romania. Astra Rail, also referred to as ARI, was previously known as Trinity and later IRS, and had built the original HOA wagons. It was not surprising then that these new wagons had a very similar appearance. The first to arrive in the UK, in April and May 2016, were the Tarmac wagons ^[24]. In an all-over mid-grey livery with large logos for Ermewa and Tarmac, the wagons were numbered in a new series as 81.70.6957.000-052. A sensible decision had been made that new wagons not intended to work abroad could be given traditional 'domestic' TOPS and design codes, even though they were now required to have 'international' numbers. The new wagons were therefore coded as HOA-B to design code HO003A and with the UIC code of 'Fabnpps' ^[25].

The first VTG/Mendip Rail hoppers arrived in August 2016 and entered service in the middle of that month. Numbers followed on from the Tarmac batch as HOA-B 81.70.6957.053 to 81.70.6957.115, the order having settled at 63 hopper wagons and 65 open boxes (TOPS JNA-T). Although very similar in appearance to the Tarmac wagons, a new design code of HO004A was issued to reflect minor dimensional differences ^[26]. Delivery of the batch was completed in October ^[27].

Mendip Rail ordered another batch of 40 hoppers in 2019, this time from lessor Touax Rail (this company having acquired the wagon fleet of GE Rail Services in 2015). The wagons were to be built by Greenbrier (Wagony Swidnica) in Poland and are likely to be similar to the IIAs ^[28].