WHEN A DOUBLE DECKER BREAKS DOWN WHAT DO YOU REPLACE IT WITH?

This is what occurs when a Double Decker breaks down, when First Ipswich Volvo B7TL/ALX 400 32653 failed to start today for a journey on the 63 to Melton, looked what stepped into the breach but mini E200 45119 RT09 JPT, meanwhile spare E200 44519 appeared again on the 60/61 town routes, while Volvo B7RLE 69010 was on the 66. Ipswich Buses wise there wasn't too many variances to the norm, one seen above was Lowlander 58 PJ53 OLA on the X3, while it's two sisters 55/57 were on the 4 assisted by Trident 22, during the morning and Trident 15 at lunch time.