It's that time of year again when leaf fall courses a real headache for the rail network. To combat this Network Rail send Rail Head Treatment Trains or RHTTs across to do battle. Here is 66715 top and tailing with 66740 form 3S70 the 0831 Broxbourne Down Tamper Sidings to Broxbourne Down Tamper Sidings via Hertford East, Seven Sisters the LTS lines giving the Goblin a wash at Walthamstow Wetlands.