is "hurtle" pronounced the same as "hurdle", where "tle" is pronounced "del"?
The words hurtle and hurdle share the consonant cluster -rdl-. The sound [l] has two functions: 1) it can be a semi-vowel (you can sing it) or 2) it can be a consonant. Some speakers pronounce the "l" in -rdl- as a semi-vowel, whereas other speakers pronounce it as a consonant. Now, as a consonant cluster, the sequence -rdl- is hard to pronounce, so what some speakers do is insert a vowel (V) between the consonants to make the word easier to pronounce:
hurtle => hurtle
hurdle => hurdle
hurtle => hurtVl
hurdle => hurdVl
Note, V represents a vowel that has been inserted for ease of articulation.