Derby's Street Lighting PFI - Derwent Street, City Centre

The existing street lighting consisted of the following items in 1997; interestingly, the ornate lanterns attached to Exeter Bridge are not listed:

Seq. No.	Lamp Number	Location	Lamp Type	Watt	Isolation Point
1	107022	OS THE COUNCIL HSE	N/A	N/A	Y
2	26804	CNR TENANT ST	SONE	400
3	26805	O/S HOTEL SITE	SONE	400
4	26806	O/S ASSEMBLY ROOMS	SONE	400
5	26807	CNR CORPORATION ST	SONE	400
6	26808	O/S MAGISTRATES CT	SONE	400
7	26809	O/S COUNCIL HOUSE	SONE	400	Y
8	26810	OS MAGISTRATES CT	SONE	400
9	26811	OS COUNCIL HOUSE	SONE	400
10	26812	CNR EXETER BRIDGE	SONE	400
11	26813	CNR EXETER BRIDGE	SONE	400
12	26814	CNR EXETER BRIDGE	SONE	400
13	26815	CNR EXETER BRIDGE	SONE	400
14	26816	OPP STUART ST	SONE	400
15	26817	O/S LONGBRIDGE HOUSE	SONE	400
16	26818	OPP PHOENIX ST	SONE	400
17	98814	OPP EXETER ST	SONE	250	Y
18	98815	JUNC SLIP RD	SONE	250
19	98816	ADJ UNDERPASS	SONE	150
23	106628	OPP ASSEMBLY ROOMS	FL	11
24	106629	OPP ASSEMBLY ROOMS	FL	8	Y
25	106630	OPP ASSEMBLY ROOMS	FL	11
26	106631	CNR CORPORATION ST	FL	8
27	106632	ON ISLAND OPP DERWENT ST	FL	8
28	106633	ON ISLAND OPP FULL ST	FL	8
29	106634	ON ISLAND OPP CORPORATION ST	FL	8
30	106635	ON ISLAND OPP DERWENT ST	FL	8
31	106636	O/S MAGISTRATES CT	T	100	Y
32	106637	SPL OPP COUNCIL HS	FL	11
33	106638	OPP COUNCIL HOUSE ON SPLITTER	FL	11
34	106639	OS COUNCIL HOUSE	T	100
35	106640	JUNC EXETER ST	FL	8
36	106641	JNC SLIP RD/U-PASS	FL	8
37	106642	JNC SLIP RD/U-PASS	FL	8
38	106643	JNC SLIP RD/U-PASS	FL	8
39	106644	JUNC U/PASS OPP NO 91	FL	8
40	106645	OPP FANNY'S SANDWICH BAR	FL	8
41	114205	ON SPLITTER ON EXETER BRIDGE	FL	8
42	114206	ON SPLITTER ON EXETER BRIDGE	FL	11
43	114207	ON SPLITTER ON EXETER BRIDGE	FL	11

The following photographs were taken on Sunday, 27th November 2011, 11th June 2011. Only six of the existing columns installed along this road were earmarked for replacement at the time, and I was fortunate to photograph them for posterity, as parked nearby at the same time was a Balfour Beatty HIAB truck; signifying their imminent removal from service.

Many of the outgoing columns along this section of the road once supported twin-lamp Atlas Alpha 8 lanterns; these were later replaced with Thorn Alpha 3s; all running 400 Watt SON-E. Over time, even most of these lanterns were replaced; leaving something of a mixture of different lanterns along the road. The PFI scheme would obviously see an end to this.

Although the lantern had clearly seen many years' use on the road, it was only relatively recently that it appeared on this column - the Alpha 3 that was previously fitted had been replaced at some point between 2008 and the date of these photographs.

The new lanterns installed along here were the 'medium' (SGS 253) version of the Iridium, with each lantern running a single 140 Watt CPO-TW lamp.

Owing to the width of the carriageway at this point, a second new column had been installed almost opposite.

At the other end of the building, another outgoing column could be glimpsed; this one ended its days supporting a Philips SGS 204.

The SGS 204 has a characteristically 'boxy' appearance.

The Iridium, by comparison, is vastly more streamlined.

Back on the other side of the road, Alpha 8s (albeit, of the later Thorn variety!) were fitted to the final four columns.

The narrow section between the lantern and the painted bracket segment would have originally been housed within the Atlas lantern - these lanterns incorporated wide-diameter spigots, and so adaptors to reduce the diameters to 42 mm had to be fitted when the Alpha 3s (originally) were fitted.

Although the old Alpha 8 columns appear shorter than their replacements, in reality, the reverse is true.

Something of the Alpha 8's Achilles heel is the plastic bowl clip - over time, the plastic becomes brittle from prolonged exposure to ultraviolet light, and can eventually break, causing the bowl to swing open. The presence of insulation tape around this particular example's bowl suggests that the clip (still visible at the front of the lantern) has indeed failed.

As the Iridium's lamp is accessed from within the lantern, and the bowl doesn't open at all, this should not be a problem that the new lantern will face.

A single-armed column overseeing the entrance to the underpass was replaced with a double-armed example, in order for the slip road leading to St Alkmund's Way to be illuminated sufficiently.

This Alpha 8 was group-switched from elsewhere; hence, the lack of a photocell.

By comparison, both of the new lanterns had their own dedicated photocells.

On the slip road itself, a single new lantern sufficed.